If a nonspecific antidiarrheal is recommended, the practitioner should review label instructions with the patient. The practitioner should stress an appropriate dosage on the basis of the patient’s age and weight, the maximum number of doses per 24 hours, and the auxiliary administration instructions. The practitioner should also explain potential drug interactions, side effects, contraindications, and the maximum duration of treatment before seeking medical help. The box Patient Education for Diarrhea contains specific information to provide patients.

Patient  education  for Diarrhea

The primary objective of self-treatment is to prevent excessive fluid and electrolyte losses. For most patients, carefully following product instructions and the self-care measures listed here will help ensure optimal outcomes.

Nondrug Measures

Infants and Children 6 Months to 5 Years

For mild-to-moderate diarrhea, indicated by three to five unformed bowel movements per day, give the child or infant an oral rehydration solution (oral rehydration solution) at a volume of 50-100 ml Vkg of body weight over 2-4 hours to replace the fluid deficit. Give additional oral rehydration solution to replace ongoing losses. Continue to give the solution for the next 4 to 6 hours or until the child is rehydrated.

If the child is vomiting, give 1 teaspoon of oral rehydration solution every few minutes.

If the child is not dehydrated, give 10 ml/kg or one-half to 1 cup of the oral rehydration solution for each bowel movement, or 2 mL/kg for each episode of vomiting.

As an alternative, to replace ongoing fluid losses, children weighing less than 10 kg should be given 60-120 mL of oral rehydration solution for each episode of vomiting or diarrheal stool, and children weighing more than 10 kg should be given 120-240 mL for each episode of vomiting or diarrheal stool.

After the child is rehydrated, reintroduce food appropriate for the child’s age, while also administering an oral rehydration solution as maintenance therapy.

If breast-feeding an infant with diarrhea, continue the breastfeeding. If the infant is bottle-fed, consult your doctor or pediatrician about substituting a milk-based formula with a lactose-free formula.

Give children complex carbohydrate-rich foods, yogurt, lean meats, fruits, and vegetables. Do not give them fatty foods or sugary foods. Sugary foods can cause osmotic diarrhea.

Do not withhold food for more than 24 hours.

Adults and Children Older Than 5 Years

For mild-to-moderate dehydration, indicated by a 3%-9% drop in body weight or three to five unformed stools per day, drink 2-4 liters of an oral rehydration solution over 4 hours.

If not dehydrated, drink one-half to 1 cup of oral rehydration solution or fluids after each unformed bowel movement.

If you have no medical conditions, you may consume sport drinks, diluted juices, salty crackers, soups, and broths until the diarrhea stops.

Do not withhold food for more than 24 hours.

Nonprescription Medications

See Table 17-6 for dosages of loperamide and bismuth sub-salicylate.

Loperamide

Note that loperamide can cause dizziness and constipation.

Do not take this agent if you are taking sedatives, antianxiety drugs, or other antidepressants.

Do not give this agent to children 2 years of age or younger. Loperamide is not recommended for children younger than 6 years, except under the supervision of a primary care provider.

If loperamide is not effective in treating your diarrhea (if no clinical improvement is observed in 48 hours), check with your primary care provider or pharmacist about using a different nonprescription medication. You may have a bacterial diarrhea or pseudomembranous colitis; these conditions require specific antibiotic therapy that loperamide cannot treat.

Bismuth Subsalicylate

Note that bismuth subsalicylate can cause a dark discoloration of the tongue and stool.

Do not take this agent if you are taking tetracyclines, quinolones, or medicines for gout (uricosurics).

Do not give this agent to children younger than 12 years.

Do not give this agent to children or teenagers who have or are recovering from influenza or chicken pox. Reye’s syndrome, a rare but serious condition, could occur.

Do not give this agent to patients with acquired immunodeficiency syndrome.

Do not take this agent if you are sensitive to aspirin, have a history of gastrointestinal bleeding, or have a history of problems with blood coagulation.

If the diarrhea has not resolved after 72 hours of initial treatment, see your primary care provider.

Monitor for excessive number of bowel movements, signs of dehydration, high fever, or blood in the stool. If any of these complications are present, discontinue bismuth subsalicylate and consult your primary care provider.

Evaluation of Patient Outcomes for Diarrhea

Many patients have mild-to-moderate diarrhea that is generally self-limiting within 48 hours. Mild-to-moderate diarrhea is managed with oral rehydration therapy, symptomatic drag therapy, and dietary measures. The patient should be monitored for dehydration by measuring body weight, vital signs, and mental alertness. With effective symptomatic relief, the patient can expect reduced frequency and normal consistency of stools, as well as relief of generalized symptoms such as lethargy and abdominal pain. As the diarrheal episode clears, the appetite will return to normal and the diet can be advanced to a regular diet.

Medical referral is necessary if any of the following signs and symptoms occur before or during treatment: high fever, worsening illness, bloody or mucoid stools, diarrhea continuing beyond 48 hours, or signs of worsening dehydration (e.g., low blood pressure, rapid pulse, or mental confusion). Also, medical referral is advised for infants, young children, frail patients of advanced age, and patients with chronic illness at risk from secondary complications (e.g., diabetes mellitus).

Key Points for Diarrhea

Limit the self-treatment of diarrhea to patients with acute diarrhea who have minimal, mild, or moderate dehydration. Patients who appear volume-depleted, weak, dizzy or hypotensive should be referred for evaluation, as should all patients with severely acute, uncontrolled, or chronic complaints involving the gastrointestinal tract.  Oral rehydration solutions are the mainstay of therapy and should be used to rehydrate patients with minimal, mild or moderate dehydration. Rehydration should be performed rapidly (i.e., within 3-4 hours).

Additional oral rehydration solution should be given to maintain hydration and replace ongoing fluid losses through diarrhea] stools and/or vomiting.

Instruct patients or their caregivers how to prepare and administer an oral rehydration solution.

Older children and adults may use sports drinks instead of an oral rehydration solution. if additional sources of sodium (e.g.. crackers and pretzels) are used concomitantly.

An age-appropriate, unrestricted diet should be initiated as soon as the patient is rehydrated. Food should be withheld for no more than 24 hours.

Loperamide and BSS may be used to help control acute diarrhea in carefully selected patients.

Antibiotic therapy is generally not indicated for patients with acute diarrhea unless it is travelers’ diarrhea.

The initial assessment of a pediatric patient should also seek to determine plausible causes of the symptoms. The common symptoms of acute gastroenteritis (e.g., vomiting, loose stools, and fever) are nonspecific findings associated with many other childhood diseases (e.g., acute otitis media, bacterial sepsis, meningitis, pneumonia, and urinary tract infections). This information is key to recommending a proper course of action, which may include self-treatment or referral to a primary care provider. A complete medication history must be assessed before a product is selected.

Physical assessment of a patient with complaints of diarrhea can provide information useful in assessing severity of the diarrhea. Checking skin turgor and moistness of oral mucous membranes will help determine the degree of dehydration. Vital signs (e.g.. pulse, temperature, respiration, and blood pressure) are important indicators of illness severity and should be routinely measured. Symptoms of moderate-to-severe dehydration may include postural (orthostatic) hypotension, defined as a drop in the systolic and/or diastolic pressure of greater than 15 to 20 mm Hg on moving from a supine to an upright position. Normally, the diastolic pressure remains the same or increases slightly, and the systolic pressure drops slightly on rising. If the blood pressure drops, the pulse should be checked simultaneously; the pulse rate should increase as blood pressure drops. Failure of the pulse to rise suggests the problem is neurogenic (e.g., diabetic patients with peripheral neuropathy) or the patient is taking a beta-blocker. The presence of orthostatic hypotension suggests that the patient has lost 1 liter or more of vascular volume, and referral for medical care is necessary.

Evidence demonstrates that probiotic therapy, especially with Lactobadllus rhamnosus GG (but also Lactobacillus casei, Lactobadllus addophilus, and Lactobadllus rented), prevents or shortens the course of mild viral diarrhea in infants and young children rhamnosus GG therapy can shorten duration of acute infectious diarrhea in children by an average of 0.7 days and reduce diarrhea frequency on day 2 of treatment by an average of 1.6 stools.Therapy with L. rhamnosus GG, L. addophilus, and .S. boulardii may also offer clinical benefit in antibiotic-associated diarrhea; a recent meta-analysis reported odds ratios favoring active treatment with these live organisms over placebo in preventing this condition. Probiotics appear to be safe; major side effects, such as Lactobadllus sepsis, have been reported only rarely. The role of probiotics in bacterial gastroenteritis and moderate-to-severe diarrhea is not supported conclusively by available evidence. The Food and Agriculture Organization of the United Nations and WHO have recognized the benefits of probiotics in the prevention and treatment of acute diarrhea. However, probiotics are not recognized as medications by FDA: their classification as dietary supplements or components of functional foods limits the health claims that can be made. Therefore, probiotics cannot be recommended to treat or prevent acute, uncomplicated diarrhea, but they can be recommended for maintenance of gastrointestinal tract function.

Several large studies performed in developing countries have shown that daily zinc supplementation in young children with acute diarrhea reduces total stool output, frequency of watery stools, and duration and severity of diarrhea. These children who are at risk for diarrheal disease are zinc-deficient because of poor nutrition; in addition, diarrhea increases intestinal losses of zinc considerably, further compromising zinc status, even in those with normal plasma zinc concentrations. Zinc deficiency is associated with impaired cellular and humoral immunity, as well as adverse gastrointestinal effects such as impaired water and electrolyte absorption, increased secretion in response to bacterial endotoxin. and decreased brush border enzymes. WHO/UNICEF recommend that children with acute diarrhea also receive zinc (10 mg of elemental zinc/day for infants younger than 6 months: 20 mg of elemental zinc/day for older infants and children) for 10 to 14 days. The role of zinc supplementation in young children with diarrhea in developed countries is not yet defined.

There is no evidence to substantiate the safety and effectiveness of herbal and homeopathic therapies in the treatment of acute diarrheal diseases; their use cannot be recommended.

Comparison of Electrolyte and Dextrose Concentrations of Household Fluids

Recommended Dosages of Antidiarrheal Agents for Acute Diarrhea

Formed stools can have high water content, and substantial water losses may continue despite the change in consistency. Moreover, reliance on drugs shifts the focus away from management of fluids and electrolytes and dietary measures, increasing the risk for potentially dangerous side effects, such as toxic megacolon. without offering additional benefits. Because intestinal viruses are the leading cause of self-limiting acute gastroenteritis, antibiotics are not routinely recommended.

Loperamide

Loperamide is a popular, effective, and safe nonprescription antidiarrheal agent. It is a synthetic opioid agonist that produces antidiarrheal effects by stimulating micro-opioid receptors located on the intestinal circular muscles. This action slows intestinal morality, allowing absorption of electrolytes and water through the intestine. Stimulation of gastrointestinal micro-opioid receptors also decreases gastrointestinal secretion, which may contribute to the drug‘s antidiarrheal effects. Loperamide is approximately 50-fold more potent than morphine and two to three times more potent than diphenoxylate in its effects on gastrointestinal motility. However, loperamide penetrates the central nervous system (CNS) poorly and therefore has a lower risk for CNS side effects. Other pharmacologic mechanisms for loperamide’s antidiarrheal effects may include disruption of cholinergic and noncholinergic mechanisms involved in the regulation of peristalsis, inhibition of calmodulin function, and inhibition of voltage-dependent calcium channels. The effects on calmodulin and calcium channels may contribute to loperamide’s antisecretory effects.

Loperamide is used to provide symptomatic relief for acute, nonspecific diarrhea. Its therapeutic effects include reduction of daily fecal volume, increased viscosity, bulk volume, and reduced fluid and electrolyte loss. It may be used when the patient is afebrile or has a low-grade fever and does not have bloody stools. Current product information provides directions for use in children as young as 2 years. However, its use in children younger than 6 years is not recommended, because it produces only modest, clinically insignificant effects on stool volume and duration of illness, with an unacceptably high risk of side effects (including life-threatening side effects such as ileus and toxic megacolon).

Loperamide is also indicated as an antidiarrheal agent in travelers’ diarrhea (in combination with antibiotics), for chronic diarrhea associated with irritable bowel syndrome and inflammatory bowel disease, and for reduction of the volume of discharge from high-output ileostomies. Off-label uses of loperamide include control of chronic diarrhea secondary to diabetic neuropathy and other conditions, as well as control of toddler diarrhea (defined as diarrhea of at least 1 month duration in an otherwise healthy, active, well-nourished child, and in whom stool examination has revealed no bacterial, viral, or protozoal pathogens). All of these uses require medical supervision.

At usual doses, loperamide has few side effects other than occasional dizziness and constipation. Other infrequently occurring adverse effects include abdominal pain, abdominal distention. nausea, vomiting, dry mouth, fatigue, and hypersensitivity reactions. Loperamide is generally not recommended for use in patients with invasive (enteroinvasive E. coll, Salmonella, Sliigella, or C. jejuni) bacterial diarrhea or antibiotic-associated diarrhea (C. difficile), because it may (rarely) worsen diarrhea or cause toxic megacolon or paralytic ileus. However, there is no evidence that these complications occur in actual practice when loperamide is used with appropriate antimicrobial therapy. Patients with symptoms suggestive of infection with invasive organisms or antibiotic-associated diarrhea (i.e., fecal leukocytes, high fever, or blood or mucus in the stool) require evaluation by a primary care provider for proper management. If abdominal distention. constipation, or ileus occurs, loperamide should be discontinued. No significant drug-drug interactions are reported for loperamide.

Bismuth Subsalicylate

Bismuth subsalicylate is effective in the treatment of acute diarrhea, including travelers’ diarrhea, significantly reducing the number of diarrhea] stools.

Bismuth subsalicylate reacts with hydrochloric acid in the stomach to form bismuth oxychloride and salicylic acid. Bismuth oxychloride is insoluble and poorly absorbed from the gastrointestinal tract; less than 1% of the administered dose is absorbed systemically. The salicylate is readily and efficiently absorbed. Both moieties are pharmacologically active; each produces effects that reduce frequency of unformed stools, increase stool consistency, relieve abdominal cramping, and decrease nausea and vomiting in children and adults. In travelers’ diarrhea, the bismuth moiety exerts direct antimicrobial effects against ETEC and EAEC, C, jejuni, and other diarrhea] pathogens, whereas the salicylate moiety exerts antisecretory effects that reduce fluid and electrolyte losses in acute diarrhea. The antisecretory effects may be mediated by-several mechanisms, including inhibition of prostaglandin synthesis, inhibition of intestinal secretion through stimulation of sodium and chloride reabsorption. or disruption of calcium-mediated processes that regulate intestinal ion transport. Bismuth subsalicylate also directly binds to enterotoxins produced by E. coli and other diarrheal pathogens; however, the clinical significance of this effect in the treatment of diarrhea is not clear.

Bismuth subsalicylate is FDA-approved for management of acute diarrhea, including travelers’ diarrhea, in adults and children 12 years of age or older. Although previously labeled for children as young as 3 years, the product is not recommended for use in young children and no longer carries labeling for children younger than 12 years. Bismuth subsalicylate is also indicated for indigestion and as an adjuvant to antibiotics for treating H.pylori-associated peptic ulcer disease.

Table Recommended Dosages of Antidiarrheal Agents for Acute Diarrhea provides dosing information for Bismuth subsalicylate.

Bismuth subsalicylate dosage forms contain various amounts of salicylate. Methyl salicylate (oil of wintergreen) is used as a flavoring agent in the suspension dosage form and the original tablet formulation. The original suspension and cherry-flavored suspension dosage forms (262 mg/l 5 mL) contain 130 mg of salicylate. whereas the original tablets (262 mg) contain 102 mg of salicylate. The caplets (262 mg) and cherry-flavored tablets (262 mg) contain 99 mg of salicylate. If a patient is taking aspirin or other salicylate-containing drugs, toxic levels of salicylate may be reached even if the patient follows dosing directions on the label for each drug.

Mild tinnitus is a dose-related side effect that may be associated with moderate-to-severe salicylate toxicity. If tinnitus occurs, the product should be discontinued and the patient referred for medical evaluation. Salicylates may cause adverse effects that are independent of the dose. Children and adolescents who have or are recovering from chicken pox or influenza are at risk of Reye’s syndrome, a rare but serious illness associated with salicylates. These patients should not use Bismuth subsalicylate. In susceptible patients, salicylate-induced gout attacks have occurred. Patients who are sensitive to aspirin (resulting in asthmatic bronchospasm) should not use Bismuth subsalicylate.

Overdosage of bismuth products can cause neurotoxicity. Blood concentrations of bismuth greater than 50 mg/L have been associated with encephalopathy characterized by slow onset of tremors, postural instability, ataxia, myoclonus, and poor concentration. Confusion, memory impairment, seizures, visual and auditory hallucinations, psychosis, delirium, and depression may also develop. Most patients gradually recover after discontinuation of the bismuth preparation; however, some develop a permanent tremor and the encephalopathy has resulted in fatality, acquired immunodeficiency syndrome patients with acute diarrhea may be at particular risk for bismuth encephalopathy, perhaps resulting from altered gastrointestinal absorption.

Harmless black staining of stool may occur, which should not be confused with melena; in addition, harmless darkening of the tongue may also occur. These frequent effects occur in more than 10% of patients treated with Bismuth subsalicylate. Bismuth salts react with hydrogen sulfide produced by bacteria in the mouth and

colon. The resulting compound, bismuth sulfide, imparts the black discoloration. It is easily removed from the surface of the tongue by brushing the tongue with a soft-bristled brush; it may also be treated by discontinuing the bismuth product.

Bismuth subsalicylate is contraindicated for nursing or pregnant women and should therefore not be used without medical advice. It also should not be used in patients with acquired immunodeficiency syndrome because of the risk for neurotoxicity. Bismuth is radiopaque and may interfere with radiographic intestinal studies.

Bismuth subsalicylate may interact adversely with a number of other drugs, particularly those that potentially interact with aspirin. The salicylate moiety can increase the risk of toxicity with warfarin, valproic acid, and methotrexate by significantly decreasing plasma protein binding of these drugs in vivo. Salicylate can also increase the plasma concentration of methotrexate by decreasing its renal clearance. The uricosuric effects of probenecid may be inhibited by salicylate; the exact mechanism underlying this interaction is not known. The bismuth moiety is a bivalent cation and may decrease absorption of other medications. such as tetracycline and quinolone antibiotics, by forming complexes with them in the gastrointestinal tract. When ciprofloxacin is used to treat travelers’ diarrhea, the patient should be instructed to discontinue Bismuth subsalicylate. Solid dosage forms of Bismuth subsalicylate contain calcium carbonate, which may enhance the cation complex interaction.

Adsorbents

Gastrointestinal adsorbents (attapulgite, kaolin, and pectin) are no longer used to treat diarrhea. Evidence supporting the safety and effectiveness of attapulgite and pectin is lacking; products containing these adsorbents have either been reformulated or withdrawn from the market. Sufficient data support the effectiveness of kaolin in improving stool consistency within 24 to 48 hours, although it does not reduce the number of stools passed. Kaolin has been deemed to be a safe and effective antidiarrheal agent by the FDA, but no single-ingredient kaolin products are currently available in the United States.

Digestive Enzymes

For patients with lactase deficiency who are intolerant of milk products, lactase enzyme preparations (Table Selected Lactase Enzyme Products) may be taken with milk or other dairy products to prevent osmotic diarrhea.

Selected Lactase Enzyme Products

Product Selection Guidelines

Table Recommended Dosages of Antidiarrheal Agents for Acute Diarrhea provides a quick reference for recommended dosages and durations ol therapy for selected antidiarrheal agents. Tables Selected Lactase Enzyme Products and Selected Antidiarrheal Products list dosage forms and primary ingredients of selected trade-name products.

Special Populations

For young children (5 years or younger), self-treatment is limited to treating dehydration with oral rehydration solutions; antidiarrheal medications are not recommended. If oral rehydration solutions are ineffective, a primary care provider must be consulted.

Elderly patients (65 years or older) should be strongly cautioned against self-treatment with antidiarrheal medications. Diarrhea in these patients is more likely to be severe possibly fatal; therefore, these patients should be referred for medical evaluation.

Selected Antidiarrheal Products

Use of nonprescription antidiarrheals may be inappropriate during pregnancy; therefore, pregnant women should consult with a primary care provider before self-treating. Loperamide is a Pregnancy Category 15 drug. Although 13SS does not have an FDA Pregnancy Category rating. BSS-containing products should be used sparingly or not at all during pregnancy because of concerns that the salicylate component may inhibit platelet function and, in the third trimester, cause premature closure of the fetal ductUS arteriosus.

Patient Factors

Selection of antidiarrheal products for older children and adults should be based on factors such as the etiology of the diarrhea, if known, prominent symptoms, potential interactions with prescribed medications, and the applicable contraindications. For example. Bismuth subsalicylate is suggested to be the preferred agent when vomiting is the important clinical symptom of acute gastroenteritis. Furthermore, BSS should not be used to treat diarrhea in an immunocompromised patients (e.g., acquired immunodeficiency syndrome and transplant recipients), because they are at increased risk for bismuth encephalopathy.

A patient’s preference for a particular dosage form or a product that requires (ewer doses is another selection criterion.

The goals of self-treatment are to (1) prevent or correct fluid and electrolyte loss and acid base disturbance. (2) relieve symptoms, (3) identify and treat the cause, and (4) prevent acute morbidity and mortality.

General Treatment Approach

Infectious diarrhea is often self-limiting. Symptomatic relief and correction of fluid and electrolyte loss are generally adequate for mild-to-moderate, uncomplicated diarrhea. Initial self-management for adults and children should focus on fluid and electrolyte replacement by administering commercially available oral solutions (e.g.. Pedialyte) in adequate doses. Simultaneous implementation of oral rehydration and specific dietary measures is appropriate for treating mild-to-moderate diarrheal illness. Symptomatic relief can also be achieved by using nonprescription antidiarrheal drugs, such as loperamide in carefully selected patients. Normal function of the alimentary tract is often restored in 24 to 72 hours without additional treatment. Severe diarrhea constitutes a medical emergency, especially in young children, and requires immediate referral for medical evaluation and treatment. Initial management with intravenous (IV) fluid therapy is necessary until perfusion and mental status improve.

Nonpharmacologic Therapy Fluid and Electrolyte Management

Correction of fluid loss and electrolyte imbalances is important, and can be accomplished by oral or IV therapy. Rehydration using oral rehydration solution (oral rehydration solution) is the preferred treatment for mild-to-moderate diarrhea. This approach is as effective as IV therapy in managing fluid and electrolytes in children with mild-to-moderate dehydration secondary to diarrhea. Because the gastrointestinal glucose-sodium cotransport mechanism is not adversely affected by most diarrheal diseases, oral rehydration solutions containing low concentrations of glucose or dextrose (2%-2.5%) can be useful in managing fluid and electrolyte balance. The sugar molecules provide very little caloric support, but they facilitate intestinal sodium and water absorption. Maximal sodium absorption occurs at a molar glucose-to-sodium ratio close to 1. In mild-to-moderate diarrhea, practitioners can safely recommend an oral rehydration solution.

According to the patient’s fluid and electrolyte status, oral treatment may be carried out in two phases: rehydration therapy and maintenance therapy. Rehydrarion over 3 to 4 hours quickly replaces water and electrolyte deficits to restore normal body composition. In the maintenance phase, electrolyte solutions are given to maintain normal body composition, and adequate dietary intake is reestablished. Although oral rehydration solutions generally are recommended for use in adults with diarrhea, there is scant evidence to support this recommendation, oral rehydration solutions may not provide any real benefit to otherwise healthy adults with mild diarrhea who can maintain an adequate fluid intake during the episode of diarrhea; for these patients, fluid and electrolyte status can be maintained by increasing intake of fluids, such as clear juices, soups, or sports drinks. Rehydration using an oral rehydration solution has no effect on the duration of diarrhea.

A variety of oral rehydration solutions are available. Most products are premixed solutions; a few are available as dry powders of glucose and electrolytes that require addition of water. The premixed products are preferred for use in children because they are safe and convenient; improper mixing of dry powders by caregivers has led to patient fluid and electrolyte complications and injury. The World Health Organization (WFIO) and United Nations Children’s Fund (UNICEF) recommend use of an oral rehydration solution containing 75 mEq/L of sodium. This oral rehydration solution significantly reduces the need for unscheduled IV therapy, stool output, and the incidence of vomiting in children with noncholera diarrhea; this formulation is also as effective as the previous formulation in children with cholera. This oral rehydration solution is also effective in adults with cholera, although transient, asymptomatic hyponatremia may develop. Rehydration solutions available in the United States contain 75 to 90 mEq/L of sodium: maintenance oral rehydration solutions contain 40 to 60 mEq/L of sodium, oral rehydration solutions have been improved with the development of cereal-based products that use complex carbohydrates (e.g., rice syrup solids) instead of glucose. Complex carbohydrates are convened into glucose at the intestinal brush border and provide more cotransport molecules while reducing the osmotic load of the oral rehydration solution. Cereal-based oral rehydration solution therapy potentially reduces stool volume by 20% to 30% in children with cholera, but this therapy may not significantly alter stool volume in children with noncholera acute diarrhea.

Selected Oral Rehydration Products

Self-care of acute

Self-care of acute

A variety of common household oral solutions have also been used for oral rehydration and maintenance. Although these solutions may be sufficient to manage mild, self-limiting diarrhea in some patients, they should be avoided if dehydration or moderate-to-severe diarrhea is present. Unlike commercial oral rehydration solutions. these remedies are not formulated on the basis of the physiology of acute diarrhea. The inappropriately high carbohydrate content and osmolality of these solutions can worsen diarrhea, and their low sodium content can contribute to the development of hyponatremia. Sports drinks may be used in older children (older than 5 veal’s) and adults it additional sources of sodium, such as crackers or pretzels, are used concomitantly. Colas, ginger ale. apple juice, sports drinks, and similar products are not recommended for infants and young children (6 months to 5 years of age) with diarrhea. Tea, another popular household remedy, is also inappropriate for children because of its low sodium content. Chicken broth is not recommended because of its inappropriately high sodium content.

Dietary Management

The traditional dietary approach to acute diarrhea has been the withdrawal of feedings and initiation of clear liquids, with a slow reintroduction of feedings over several days. However, oral intake does not worsen the diarrhea, clinically significant nutrient mal-absorption is uncommon in acute diarrhea, and bowel rest is generally not necessary. On the contrary, during acute diarrhea, patients are able to absorb 80% to 95% of dietary carbohydrates. 70% of fat and 75% of the nitrogen from protein. Early refeeding in combination with maintenance oral rehydration improves outcomes of acute diarrhea in children by reducing duration of the diarrhea, reducing stool output, and improving weight gain. It is inappropriate to withhold food for longer than 24 hours. A normal, age-appropriate diet should be reintroduced once the patient has been rehydrated. which should take no longer than 3 to 4 hours to accomplish. Most infants and children with acute diarrhea can tolerate full-strength breast milk and cow milk. The familiar BRAT diet (bananas, rice, apple-sauce, and toast) is not recommended; it provides insufficient calories, protein, and fat, especially in situations of strict or prolonged use. Patients (or their parents) should be advised to avoid tatty foods, foods rich in simple sugars that can cause osmotic diarrhea, and spicy foods that may cause gastrointestinal upset. Caffeine-containing beverages should also be avoided, given that caffeine can increase cyclic adenosine monophosphate levels, which promote fluid secretion and may worsen diarrhea. There is no evidence that fasting or dietary modification influences outcomes of acute diarrhea in adults; however, similar guidelines can be applied if a normal diet is not tolerated.

Preventive Measures

Infectious diarrhea, especially acute viral gastroenteritis, often occurs in congregate living conditions such as day care centers and nursing homes through person-to-person transmission. Isolating the individual with diarrhea, washing hands, and using sterile techniques are basic preventive measures that reduce the risk among such populations and their caregivers. Strict food handling, sanitation, and other hygienic practices help control transmission of bacteria and other infectious agents.

Short-term bismuth subsalicylate (Bismuth subsalicylate) prophylaxis is frequently recommended to provide protection against travelers’ diarrhea; however. FDA has deemed available data insufficient to support prophylactic use of Bismuth subsalicylate. Antibiotics with reliable activity against enteropathogens in the region of travel provide effective prophylaxis. However, prophylactic antimicrobial agents are not currently recommended for most travelers. Prophylactic antibiotics may be considered for short-term travelers who are high-risk hosts (e.g., immunosuppressed patients) or for those critical trips during which even a short bout of diarrhea could impact the purpose of the trip.

Diarrhea can be classified as osmotic, secretory, inflammatory, or motor, depending on the underlying pathophysiologic mechanisms that disrupt normal intestinal function. The common mechanisms of acute diarrhea are osmotic and secretory, whereas motor and exudative mechanisms commonly underlie chronic diarrheal illnesses. Table Clinical Classification of Diarrhea correlates the clinical groups and mechanism with their most common causes.

Bacterial and viral enterotoxins play a role in the pathophysiology ol secretory diarrheas. Enterotoxins elaborated by E. coli and Vibrio cholera evoke the release of endogenous secretagogues that mediate secretory reflexes, including serotonin, substance P, and vasoactive intestinal peptide. Some enterotoxins, such as cholera toxin, can directly stimulate gastrointestinal secretomotor neurons to increase intestinal secretion. C. difficile enterotoxin A also injures enterocytes to evoke a necroinflammatory response that causes a secretory diarrhea. Rotaviruses produce an enterotoxin that causes a calcium-mediated secretory diarrhea. In addition, inflammatory mediators (e.g., interleukins 1 and 6. prostaglandins, substance P, tissue necrosis factor-alpha, and platelet-activating factor) evoked by enteric-infection stimulate a characteristic gastrointestinal motility pattern that leads to the urgent defecation associated with diarrhea. This altered motility also causes abdominal cramps.

Stool characteristics give valuable information about the diarrhea‘s pathophysiology. For example, undigested food particles in the stool suggest disease of the small intestine. Black, tarry stools may indicate upper gastrointestinal bleeding, and red stools suggest possible lower bowel or hemorrhoidal bleeding or simply recent ingestion of red food (e.g.. beets) or drug products (e.g., rifampin). Diarrhea originating from the small intestine is characterized by a marked outpouring of fluid high in potassium and bicarbonate. Passage of many small-volume stools suggests diarrhea with a colonic disorder. Yellowish stools may suggest the presence of bilirubin and a potentially serious pathology of the liver. A whitish tint to the stool suggests a fat malabsorption disease. Patients who have stool containing blood or mucus need medical evaluation.

Fluid and electrolyte imbalance is the major complication of diarrheal illness. Therefore, assessment of the patient’s risk for dehydration and the degree of dehydration present is key in determining the appropriateness of self-care and the need for medical referral. The specific signs and symptoms of dehydration are associated with the severity of the diarrhea, as well as the etiology and degree of fluid and electrolyte losses (Table Assessment of Dehydration and Severity of Acute Diarrhea).

Healthy patients with uncomplicated acute diarrhea usually improve clinically within 24 to 4.S hours. If the condition remains the same or worsens after 48 hours of onset, medical referral is necessary to prevent complications. Certain medical conditions cm increase the risk for dehydration. Referral for medical care should be considered for patients with diabetes mellitus severe cardiovascular or renal diseases, or multiple unstable chronic medical conditions. Specifically, medical evaluation is indicated for:

Severe vomiting or dehydration.

Passage of multiple small-volume stools containing blood and mucus.

Fever of 38.5°C (101.3°F) or higher.

Clinical Classification of Diarrhea

Assessment of Dehydration and Severity of Acute Diarrhea

Passage of six or more unformed stools in 24 hours or illness lasting 48 hours or longer.

Diarrhea accompanied by severe abdominal pain in a patient older than 50 years.

Patients with severe abdominal pain, particularly those older than 50 years, may have a complicating illness such as ischemic bowel disease. Immunocompromised patients, such as those receiving cancer treatment, organ transplant recipients, and patients with acquired immunodeficiency syndrome, also need medical evaluation, because their diarrhea will often be complicated and difficult to manage. Self-care medication may also be inappropriate for diarrhea during pregnancy, and pregnant women should consult with a primary care provider before self-treating.

Children younger than 5 years and adults older than 65 years are at greater risk for complications than other age groups. In developed countries, most children experience complete recovery, although some die of complications. In the United States, approximately 300 to 450 children die annually from acute gastroenteritis; most of these deaths occur in infants. Children 2 years of age or younger are likely to suffer complications that require hospitalization. In newborns, water may comprise up to 75% of total body weight: severe diarrhea may cause water loss equal to 10% or more of body weight. After 8 to 10 bowel movements within a 24-hour period, a 2-month-old infant could lose enough fluid to cause circulatory collapse and renal failure. Moderate-to-severe diarrhea in infants requires evaluation by a primary care provider.

In recent years, deaths from viral and bacterial gastrointestinal infection have increased most sharply among people 65 years of age and older whose diarrhea is likely to be more severe than in other adults: older adults currently experience the highest rate of death from enteric infections.

Epidemiologic factors that increase the risk for particular infectious diarrhea] diseases or their spread include attendance or employment at day care centers, occupation as a food handler or caregiver, congregate living conditions (e.g., nursing homes, prisons, and multifamily dwellings), consumption of unsafe foods (e.g., raw meat, eggs, and shellfish), and presence of medical conditions, such as acquired immunodeficiency syndrome, that predispose to infectious diarrhea.

Acute diarrhea may also be caused by poisoning, medications, intolerance of certain foods, or various non-gastrointestinal (gastrointestinal) acute or chronic illnesses.

Viral Gastroenteritis

Norovinises are the most common viral pathogens, accounting for approximately 70% to 75% of viral gastroenteritis. The symptoms and clinical course are described in Table Common Infectious Diarrheas and Their Treatment. The virus is usually transmitted by contaminated water or food. Community-wide outbreaks may result when municipal water supplies become contaminated. Recent outbreaks of norovirus gastroenteritis on cruise ships have received attention, although 60% to 80% of all outbreaks occur on land.” Contaminated food is the most frequently identified vehicle of infection in this setting.” Person-to-person transmission may also be important, and it has been suggested that infected cruise ship crew members may serve as reservoirs of infection for passengers.

Rotaviruses account for about 12% of all acute gastroenteritis and up to 50% of infantile gastroenteritis. The incidence of rotavirus infection is highest among children between 3 to 24 months of age. The peak infectious period is during the winter months (November to February). Spread is by the fecal-oral route. Clinical features are presented in Table Common Infectious Diarrheas and Their Treatment. Treatment is usually restricted to fluid and electrolyte therapy. Severe dehydration and electrolyte disturbances, however, can occur and may result in death. In 2006, a live, oral vaccine to prevent rotavirus gastroenteritis was licensed by the Food and Drug Administration (FDA) for routine use in healthy infants. In clinical trials, this vaccine prevented 74% of all rotavirus gastroenteritis cases and 98% of the severe cases, and reduced the need for hospitalization attributable to rotavirus gastroenteritis by 96%.

Other, less frequent viral causes of gastroenteritis include adenoviruses, astroviruses, and hepatitis A virus.

Bacterial Gastroenteritis

Bacterial pathogens cause approximately 5 million episodes of acute gastroenteritis in the United States each year. Pathogens most commonly responsible for these cases, in order of decreasing incidence, are Cainpylobacicr sp.. Salmonella sp., Shigella sp., Eschcrichia coli (including 0157:H7, non-0157:H7 Shigatoxin-producing E. coli |STEC), enterotoxigenic E. coli, and other diarrheagenic strains), Siapliylococcus sp., Clostridium sp., Yersinia ciucrocoliliai, and Bacillus cereus. Aeromonas sp. are being increasingly recognized as enteropathogens. particularly in food-borne disease; Bacteroidesfiagilis, Klebsiella oxytoca, and Laribacter honkongensis are newly identified causes of acute diarrhea.Cainpylobacicr is identified as the etiologic agent two to seven times more frequently than Salmonella, Shigella, or E. coli.

Common Infectious Diarrheas and Their Treatment

Key: acquired immunodeficiency syndrome, acquired immunodeficiency syndrome.

Empirical therapy with prescription antibiotics (azithromycin, erythromycin) should be considered for patients with febrile diarrheal illness, especially if moderate-to-severe invasive disease is suspected, and for patients in whom supportive therapy fails to manage symptoms. Ciprofloxacin has been recommended, but it is no longer considered a first-line agent, because many Campylobacter strains are resistant to fluoroquinolones.

Antibiotics are not indicated routinely for Salmonella gastroenteritis; antibiotic therapy is used in young infants and children who fail to respond to supportive treatment, who do not spontaneously remit, or who are at increased risk of disseminated disease. Antibiotic therapy is also indicated for suspected bacteremia in patients at high risk for this complication. These include patients who appear to be toxic with high fever (>102.2°F [39°C]); infants (<3 months); older adult patients (>65 years); patients with cancer, immunodeficiency (e.g., acquired immunodeficiency syndrome), or hemoglobinopathy (e.g., sickle cell disease); patients receiving corticosteroids or on hemodialysis; and patients with vascular grafts or prosthetic joints. Duration of antimicrobial therapy is usually 7-10 days.

Antibiotic treatment with fluoroquinolones, azithromycin, or rifaximin (prescription antibiotics) is given for travelers’ diarrhea caused by E. coli. Trimethoprim/sulfamethoxazole is no longer an optimal choice because of increasing worldwide resistance. Antibiotic treatment is not recommended for gastroenteritis caused by E. coli 0157:H7, because the treatment is likely to enhance toxin release and may increase risk for hemolytic uremic syndrome.

Self-treatment of giardiasis is not appropriate; metronidazole, nitazoxanide, tinidazole, quinacrine, furazolidone, and paromomycin are effective prescription alternatives for treating giardiasis.

Self-treatment of cryptosporidiosis is not appropriate. Symptomatic relief of cryptosporidiosis may be achieved in acquired immunodeficiency syndrome patients by adding paromomycin and azithromycin (both prescription antimicrobial agents) to the patient’s antiretroviral therapy.

Self-treatment of amebiasis is not appropriate; prescription therapy with metronidazole followed by either paromomycin or iodoquinol is the preferred treatment.

Bacteria cause diarrhea through elaboration of an enterotoxin (e.g., toxigenic E, coli and Siapliylococcus aurcus) or by directly invading the mucosal epithelial cells (e.g., Shigella, Salmonella, Yersinia, Cainpylobacicr jejuni, and invasive E. coli). Patients with diarrhea caused by toxin-producing agents have a watery diarrhea, which primarily involves the small intestine. If the large intestine is the site of attack, invasive organisms produce a dysentery-like (bloody diarrhea) syndrome characterized by fever, abdominal cramps, tenesmus (straining), and the frequent passage of small-volume stools that may contain blood and mucus. Clinical features of common bacterial diarrheas are presented in Table Common Infectious Diarrheas and Their Treatment.

Food-borne transmission of pathogens accounts for 36% of acute gastroenteritis episodes in the United States; of these infections, 30% are due to bacteria, 67% to viruses, and 3% to protozoa. Recent surveillance statistics on the incidence of food-borne illnesses in the United States document that Salmonella and Cainpylobacicr, which caused 14.81 and 12.71 cases of illness per 10(1,000 population in 2006, respectively, are the most frequently diagnosed bacterial pathogens, followed by Shigella (6.09 cases per 100,000 population). Shigatoxin-producing coli 0157:H7 (1.31 cases per 100.000 population). Yersinia (0.35 cases per 100.000 population). Vibrio (0.34 cases per 100,000 population), and Lisieria (0.31 cases per 100.000 population).

Outbreaks of food-borne bacterial infection have been traced to poor sanitary conditions in meat-processing plants and various retail outlets (e.g.. grocery stores and restaurants). Outbreaks of infection have also been associated with specific foods, such as milk (Cainpylobacicr), raw eggs (Salmonella), chicken (Cainpylobacicr, Salmonella), melons (Lisieria). hummus (Lisieria), and raspberries (Cyclospora). Therefore, an attentive and thorough history regarding food intake before the onset of diarrhea is essential in identifying a probable cause. For example, toxin-producing S. aureus grows rapidly in food (especially salads, custard, sausage, ham, dairy products, and poultry). Upon ingestion the enterotoxin provokes nausea and vomiting with diarrhea within 6 hours. In contrast, the incubation period for Salmonella, which is harbored on raw foods and particularly on eggs, is 12 to 24 hours. These microbes invade the mucosal layer of the gastrointestinal tract and disrupt the normal absorptive-secretory mechanisms. Fever, malaise, muscle aches, and profound epigastric or peri-umbilical discomfort with severe anorexia suggest an infectious, inflammatory disease of the large intestine. Abdominal pain, vomiting, and diarrhea suggest viral gastroenteritis, and symptoms usually persist for 2 to 3 days before gradually subsiding.

A major public health issue is contamination of food, especially undercooked hamburger and unpasteurized apple cider with E. coli 0157:H7 and other STECs. Recently, outbreaks of STEC OI57 have been caused by consumption of contaminated spinach, lettuce, and raw milk. The toxins produced by these organisms cause an acute bloody diarrhea, but they may also be associated with serious, potentially fatal systemic complications such as hemolytic uremic syndrome or thrombotic thrombo-cytopenic purpura.

Other causes of food-borne gastroenteritis include Lisieria monocyiogeiics, (Cyclospora cayeiancnsis, and viruses. Noroviruses and rotavirus have also been implicated in food-borne disease.

Travelers’ diarrhea is a secretory diarrhea acquired, for the most part, through ingestion of contaminated food or water. This acute diarrhea is usually caused by bacterial enteropathogens. It affects millions of tourists visiting foreign countries or U.S. border areas with poor sanitation. Although Salmonella. Shigella, Cainpylobacicr, Eniamoeba hisiolylica, Ciardia, and rotavirus have all been implicated in the disease. E. coli is the most common infecting organism in travelers’ diarrhea. Two strains, enterotoxigenic E. coli (ETEC) and enteroaggregative E. coli (EAEC), are responsible for most cases. ETEC is found in up to 40% of travelers with diarrhea in various areas around the world; EAEC is almost as common, causing approximately 25% of cases. The causative organisms are found most often on foods such as fruits, vegetables, raw meat, seafood, and even hot sauces; less commonly, pathogens are found in the local water, including ice cubes. After ingestion, ETEC produces two plasmid-mediated enterotoxins that cause symptoms: one of these enterotoxins is Structurally, functionally, and immunologically closely related to cholera toxin. The pathogenic mechanisms underlying diarrhea caused by EAEC are not well understood these organisms may produce disease through elaboration of an enterotoxin, a cytotoxin, or some other means. The diarrheal disorder caused by these organisms is characterized in Table Common Infectious Diarrheas and Their Treatment. Patients may experience between three and eight (or more) watery stools per day, with symptoms usually subsiding over 3 to 5 days.

Bacterial pathogens not only cause acute illness, they can also cause functional bowel disorders, including postinfectious irritable bowel syndrome (irritable bowel syndrome), for 6 months or longer after a bout of acute gastroenteritis. In 10% to 30% of patients, bowel dysfunction persisted 6 months after infectious diarrhea caused by Cainpylobacicr, Shigella, Salmonella, and diarrheagenic coli (ETEC and EAEC). Irritable bowel syndrome is diagnosed in 4% to 10% of patients 1 to 2 years after an episode of acute bacterial gastroenteritis.

Protozoal Diarrhea

Diarrhea may also be caused by protozoa, including Ciardia lamblia, E. hisiolylica, Isospora belli, and Crypiosporidinm sp. (Table Common Infectious Diarrheas and Their Treatment). No nonprescription therapies are available to manage diarrhea caused by these pathogens and self-management is inappropriate.

Food-Induced Diarrhea

Food intolerance can provoke diarrhea and may result from a food allergy or ingestion of foods that are excessively fatty or spicy, or contain a high amount of roughage or many seeds. Carbohydrates in the diet commonly include the disaccharides lactose and sucrose, which are normally hydrolyzed to mono-saccharides by the enzyme lactase. When these disaccharides are not hydrolyzed. they pool in the lumen of the intestine, where they not only ferment but also produce an osmotic imbalance and pH change. The resulting hyperosmolarity draws fluid into the intestinal lumen, causing diarrhea. Lactase enzymatic activity may be reduced in intestinal disorders such as infectious diarrhea and gastrointestinal allergy. Acute viral diarrhea may cause temporary milk intolerance in patients of all ages. Lactase deficiency resulting from viral gastroenteritis is short-lived and is particularly problematic during the first few days of the disease. Infants bom with lactase deficiency and adults who develop lactase deficiency are intolerant of cow’s milk and milk-based products. Lactase enzyme products are effective treatments for some patients.

quate fluid intake, and reasonable exercise. Individuals may not understand the importance of these factors in the development of constipation and how simple lifestyle changes can restore relatively normal bowel function without laxative use. If a laxative is needed, the health care provider should explain why a particular type of laxative is appropriate for the present situation, how to use the laxative, when to expect to see results, what adverse effects could occur, and what precautions to take. The box Patient Education for Constipation lists specific information to provide patients.

Patient  education   for Constipation

The objectives of self-treatment are to relieve constipation and restore “normal” bowel functioning by implementing (1) dietary and lifestyle measures and/or (2) the safe use of laxative products. For most patients, carefully following the product instructions and the self-care measures listed here will help ensure optimal therapeutic outcomes.

Nondrug Measures

Use nonpharmacological methods such as a high-fiber diet (goal is 25-35 grams per day), adequate fluid intake, and exercise to foster regular bowel movements.

Increase dietary fiber by eating foods containing wheat grains, oats, fruits, and vegetables.

Avoid constipating foods such as processed cheeses and concentrated sweets.

Drink plenty of fluids (six to eight 8-ounce glasses a day) to aid in stool softening and to facilitate fecal evacuation.

Develop and maintain a routine exercise program. Walking can be beneficial if your cardiovascular system is healthy and if you have no other apparent health risks.

Establish a regular pattern for bathroom visits. Do not delay responding to the urge to defecate; allow adequate time for elimination in a relaxed, unhurried atmosphere.

Maintain general emotional well-being and avoid stressful situations.

Nonprescription Medications

Do not routinely take laxatives if your bowel habits are interrupted for a day or two, or to routinely “clean your system.”

Do not give laxatives to children younger than 6 years unless the use is recommended by a primary care provider.

If you have kidney or liver disease, heart failure, hypertension, or other conditions requiring sodium, potassium, magnesium, or calcium restriction, do not use laxative products whose maximum daily dose contains more than 345 mg (15 mEq) of sodium, 975 mg (25 mEq) of potassium, 600 mg (50 mEq) of magnesium, or 1800 mg (90 mEq) of calcium.

Consult your primary care provider before using laxatives if you currently have or have a history of any of the following conditions: colectomy, ileostomy, diabetes, heart disease, kidney disease, or swallowing difficulties.

Consult a primary care provider or pharmacist before using a laxative product if you are taking anticoagulants (blood thinners), digoxin (a heart medicine), sodium polystyrene sulfonate (a treatment for high potassium levels), or tetracycline antibiotics.

Avoid taking laxatives within 2 hours of taking other medications.

Take most laxatives at bedtime, especially if more than 6-8 hours are required to produce results.

Discard any medications that are outdated, that appear to have been tampered with, or that have an unusual appearance.

Bulk-Forming Laxatives

Unless a rapid effect, such as cleaning out the bowel for a diagnostic procedure or X-ray, is needed, take a bulk-forming laxative. Be sure to drink at least 8 ounces of fluid with each dose to prevent intestinal obstruction.

Use bulk-forming agents with caution if you have diabetes

or are on a carbohydrate-restricted diet. These agents have a high caloric content per dose and contain sugar.

Do not give sugar-free bulk-forming products to patients with phenylketonuria. Such products may contain aspartame, which contributes excessive levels of phenylalanine, an amino acid these patients cannot metabolize.

Lubricant Laxatives

Do not give mineral oil to children younger than 6 years of age, pregnant patients, older patients, or patients taking anticoagulants.

Do not take mineral oil with emollient laxatives.

To avoid delaying the absorption of foods, nutrients, and vitamins, do not take mineral oil within 2 hours of eating.

Saline Laxatives

Take saline laxatives on an empty stomach; the presence of food will delay action.

Do not take saline laxatives every day.

Do not give these laxatives orally to children younger than 6 years of age or rectally to infants younger than 2 years of age.

Hyperosmotic Laxatives

Do not take the medication in larger than recommended amounts.

When using PEG 3350 (MiraLAX), use the provided cap to measure the prescribed dose. Mix the powder with a full glass (8 ounces or 240 milliliters) of liquid such as water, juice, soda, coffee, or tea.

Use of glycerin may be inappropriate in patients with a previous condition that caused rectal irritation.

Stimulant Laxatives

Do not use castor oil to treat constipation except under the advice of a primary care provider.

A Do not take laxatives if you have any symptoms of appendicitis (i.e., abdominal pain, nausea, vomiting), rectal bleeding, painful anal or rectal conditions, bloating, or cramping. See a primary care provider immediately.

A If symptoms of constipation are unrelieved by nondrug measures or by 1 week of any laxative treatment, see a primary care provider. Chronic constipation may be a symptom of an underlying medical condition.

Evaluation of Patient Outcomes for Constipation

Constipation often presents with a great degree of variability among individuals. Although a decrease in frequency of bowel movements is typically associated with constipation, difficulty in passing stools and a decrease in the amount passed are also common complaints. The type, severity, and chronicity of symptoms are important determinants in selecting the most appropriate treatment modality. Once therapy has been selected, effectiveness is determined by how rapidly constipation is relieved and to what degree normal bowel habits have been restored. For acute constipation, dietary changes and exercise or the use of bulk-forming laxatives may take several days to weeks to provide relief. Stimulant laxatives usually provide results within 24 hours: osmotic laxatives provide more immediate relief, usually within 15 minutes to 3 horn’s for oral preparations. Laxative enemas, often used when fecal impaction accompanies constipation, can produce evacuation within minutes. If initial treatment of constipation is ineffective, therapy should be repeated according to product-specific directions.

If an adequate response is not achieved after a short period of laxative use, usually within 1 week, chronic constipation should be considered. Follow-up should be attempted to assess whether the patient should receive further evaluation by a primary care provider.

Self-medication with laxatives can be safe and effective if used as directed and not used excessively. Close monitoring of the frequency and duration of laxative use can be beneficial in determining whether normal bowel habits are actually reestablished between bouts of constipation or if a more severe condition exists. It a laxative must be continued for an extended period such as in chronic constipation, bulk-forming agents are preferred. However, the need for frequent laxative use should be discussed with a primary care provider, because frequent use may be a sign of (1) a more severe form of constipation. (2) a side effect of a medication, or (3) an underlying medical problem. Overuse or extended use of some laxatives can alter the normal physiologic functioning of the gut and. in some persons, may lead to a dependence on laxatives for bowel function. Adhering to a diet high in fiber and drinking plenty of fluids can aid in preventing constipation and should be continued even during periods when bowel habits are normal.

Key Points for Constipation

• Constipation is a decrease in frequency of fecal elimination characterized by the difficult passage of hard, dry stool.

Successful treatment of constipation depends on careful identification of the cause.

►   In determining whether self-treatment or medical referral is appropriate, the clinician also needs to know the case history and current symptoms as well as the patient’s reason for desiring to purchase a laxative.

If the case history discloses a sudden change in bowel habits that has persisted for 2 weeks, the patient should be immediately referred to a primary care provider.

• For most cases of simple constipation, a balanced diet, exercise, and adequate fluid intake should be helpful.

In addition, patients should always be encouraged to establish a regular pattern for bathroom visits and never delay responding to the urge to defecate.

► Special circumstances and patient characteristics (i.e., pregnancy or age) should be considered when assessing the need for self-medication.

Therapy with any laxative product should be limited, in most cases, to short-term use.

► Laxative treatment for constipation should not be recommended if the patient exhibits “red flag” or “alarm” symptoms (sudden changes in stool, recent weight loss, presence of abdominal pain, blood in the stool, fever, anorexia, and nausea and vomiting), painful anal or rectal conditions, bloating, or cramping.

Patients should be advised to avoid taking laxatives within 2 hours of other medications to reduce the potential for drug interactions.

The cost of laxative products is variable; however, concomitant use of nonpharmacologic measures may lead to lower expenditures on laxative products for the patient with simple constipation.

Routine use oflaxative enemas includes preparing patients for surgery, child delivery, and gastrointestinal radiologic or endoscopic examinations, as well as for treating certain cases of constipation. The enema fluid determines the mechanism by which evacuation is produced. Tap water and normal saline create hulk through an osmotic volume effect; vegetable oils lubricate, soften, and facilitate the passage of hardened fecal matter: and the irritant action of soapsuds produces defecation. However, prolonged rectal irritation may occur after soap enemas and may result in proctitis or colitis. Therefore, soap enemas are not recommended.

The popular sodium phosphate/sodium biphosphate enemas (e.g.. Fleet) fall into the category of saline laxatives. These agents are more efficient and effective than tap water, soapsuds, or saline enemas. Because they can alter fluid and electrolyte balance significantly with prolonged use, chronic use of these products is not warranted for controlling constipation.

A properly administered enema cleans only the distal colon, most nearly approximating a normal bowel movement. Proper administration requires that the diagnosis, the enema fluid, and the technique of administration be correct. Improperly administered, an enema can produce fluid and electrolyte imbalances. Enema fluids have caused mucosal changes or spasm of the intestinal wall. Water intoxication has resulted from the use of tap water or soapsuds enemas in the presence of megacolon. A misdirected or inadequately lubricated nozzle may cause abrasion of the anal canal and rectal wall or may cause colonic perforation.

Patients should be advised to follow all directions carefully when using these products. The patient should lie or be placed either on the left side with knees bent or in the knee-to-chest position. If the patient is in a sitting position, use of an enema clears only the rectum of fecal material. The solution should be allowed to flow into the rectum slowly; if the patient is uncomfortable, the flow is probably too fast. One pint (500 mL) or less of properly introduced fluid usually produces adequate evacuation if it is retained until definite lower abdominal cramping is felt. As long as 1 hour may be needed for the entire procedure.

Bisacodyl-containing suppositories are promoted as replacements for enemas when the distal colon requires cleaning. Suppositories that contain bisacodyl are used for postoperative, antepartum, and postpartum care, and are adequate in preparing for proctosigmoidoscopy. Although bisacodyl suppositories are prescribed and are used more often than other suppositories, some clinicians still prefer enemas as agents for cleaning the lower bowel. Glycerin suppositories are useful in initiating the defecation reflex in children and in promoting rectal emptying in adults.

Administration of Rectal Suppositories or Enemas

Enemas

1. If someone else is administering the enema, lie on your left side with knees bent or in the knee-to-chest position. Position A is preferred for children older than 2 years. If self-administering the enema, lie on your back with your knees bent and buttocks raised. A pillow may be placed under the buttocks.

2.  If using a concentrated enema solution, dilute solution according to the product instructions. Prepare 1 pint (500 mL) for adults and 1/2 pint (250 mL) for children.

3.  Lubricate the enema tip with petroleum jelly or other non-medicated ointment/cream. Apply the lubricant to the anal area as well.

4.  Gently insert the enema tip 2 (recommended depth for children) to 3 inches into the rectum.

5.  Allow the solution to flow into the rectum slowly. If you experience discomfort, the flow is probably too fast.

6.  Retain the enema solution until definite lower abdominal cramping is felt. The parent/caregiver may have to gently hold a child’s buttocks closed to prevent the solution from being expelled too soon.

Suppositories

1. Gently squeeze the suppository to determine if it is firm enough to insert. Chill a soft suppository by placing it in the refrigerator for a few minutes or by running it under cool running water.

2.  Remove the suppository from its wrapping.

3.  Dip the suppository for a few seconds in lukewarm water to soften the exterior.

4.  Lie on your left side with knees bent or in the knee-to-chest position. Position A is best for self-administration of a suppository. Small children can be held in a crawling position.

5.  Relax the buttock just before inserting the suppository to ease insertion. Gently insert the tapered end of the suppository high into the rectum. If the suppository slips out, it was not inserted past the anal sphincter (the muscle that keeps the rectum closed).

6.  Continue to lie down for a few minutes, and hold the buttocks together to allow the suppository to dissolve in the rectum. The parent/caregiver may have to gently hold a child’s buttocks closed.

7.  Remember that the medication is most effective when the bowel is empty. Try to avoid a bowel movement after insertion of the suppository for up to 1 hour so that the intended action can occur.

Positions

Patient Preferences

Liquid formulations of emollients may be made more palatable if mixed with juices or milk. The most commonly used products that contain castor oil are the more palatable emulsions. When plain castor oil is used, it may be administered with fruit juice or a carbonated beverage to mask its unpleasant taste. Chilling the oral form of a sodium phosphate-type product or taking it with ice seems to make it more palatable. Palatability may also be improved by drinking the product with a citrus fruit juice or with a citrus-flavored carbonated beverage.

Alternative and Complementary Therapies

Patients frequently treat constipation with a botanical product. Common dietary supplements include buckthorn, flaxseed, plantago, and senna. Although many of the commercially available stimulant and bulk-forming laxatives are derived from plants, some consumers prefer to use a “more natural” version of these products. In recent years. FDA has banned the use of aloe and cascara in nonprescription stimulant laxatives. Both agents are classified as generally unsafe and not effective. However, they are commonly found in many herbal teas, extracts, and pills. Individuals should either limit or avoid use of these products. They should also be cautioned against the use of botanical laxatives during pregnancy or breast-feeding, and in children.

Consumers are increasingly selecting dietary supplements that contain probiotics to promote regularity of the digestive tract. Fennented dairy products containing Bifidobacterium aitimalis DN-173 010 (in Activa yogurt) can usually be found in the refrigerated dairy section of the supermarket. Other products containing Bifidobacterium infantis 35624 (contained in Aligh) are available as oral capsules. These probiotics interact with the bacteria in the digestive tract and are marketed to improve the transit of food through the system and regulate digestion. Users should be cautioned that increased bloating and gas are common with consumption of these products. Probiotics, in general, are regarded as well tolerated and safe; however, the beneficial effects in preventing or relieving constipation have not been substantiated.

Selected Laxative Products

Children typically describe constipation as a difficulty in passing stools. Straining to pass large or hard stools can be painful. The child may then avoid or withhold bowel movements, resulting in worsening symptoms and fear of toileting. Normal frequency of bowel movements varies with the age of a child, making it difficult to recognize abnormal bowel habits. Because stooling becomes less frequent with increasing age. what may be a normal stooling pattern may be misdiagnosed as constipation. Parents seek advice for children of all ages when stooling patterns differ from what the parent perceives to be normal. Laxatives are often administered to children in an attempt to facilitate the passage of stools and to reestablish a normal stooling pattern. As a result, indiscriminate use of laxatives may result if the child has a stooling pattern that is changing or when other constipating factors are present. Children should be encouraged to establish a regular pattern of bowel movements and to avoid withholding of stools when the urge to have a bowel movement occurs. The clinician should do a thorough assessment of possible causes for constipation, and always consider a child’s age and any previous laxative use when recommending laxative products. The route of administration and the taste of oral products may be especially significant in children. Laxative use can be avoided in older children by encouraging them to adhere to suggested dietary guidelines to improve stool regularity.

If medications are indicated in children younger than 5 years, glycerin suppositories may initiate the defecation reflex with onset usually within 15 to 60 minutes. Barley malt extract (malt soup extract) is relatively safe for infants younger than 2 months. Breast-fed infants may receive 6 to 10 mL in 2 to 4 ounces of water or fruit juice twice daily. Bottle-fed infants may receive 7.5 to 32 mL in a day’s total formula, or 5 to 10 ml. every second feeding. Mineral oil is not recommended because of the risk of aspiration. Stimulant laxatives and phosphate enemas should be avoided.

In children who have fecal impaction, disimpaction can usually be achieved by the use of oral medications, enemas, or a combination of both. For infants younger than 1 year, glycerin suppositories or an enema can be used. However, some experts suggest avoiding enemas in infants younger than I year; if an enema is necessary, it should be done under the direction of a primary care provider.” For children I year and older, bisacodyl, magnesium citrate, PEG electrolyte solutions (e.g., Colyte and Golytely) or PEG solutions without electrolytes (MiraLAX in an initial dose of 1-1.5 g/kg/day for 3 days) are oral medications that may be useful for fecal impaction. Enemas containing phosphate soda or saline can also achieve disimpaction, although the oral route is less invasive. Parents should be cautioned that enemas act fast but can be traumatic for children. Saline agents can lead to salt and water retention. Use in children younger than 2 years may lead to electrolyte abnormalities, such as hypocalcemia, tetany. hypematremia. dehydration, and hyperphosphatemia. Electrolyte levels in these patients require careful monitoring.

When fecal impaction is not present, treatment of constipation in infants should consist of glycerin suppositories or oral juices containing light or dark com syrup (1-3 mL/kg/day divided into two feedings per day). In children older than I year. milk of magnesia or PEG 3350 without electrolytes can be given according to age-appropriate dosage recommendations.” In general, stimulants should be avoided, as should excessive use of enemas.

Patients of Advanced Age Constipation is more common in adults as they advance in age. Older adults (e.g.. >65 years old) frequently describe constipation as straining to move bowels and report fewer stools per week. The aging process is associated with physiologic changes that prolong the transit time through the colon, which decreases the perception of the urge to defecate. Constipation in older adults can be precipitated or aggravated by-conditions such as neuromuscular disorders, confusion, dementia, and depression. In addition, the older population tends to have multiple medical conditions and take multiple medications that may contribute to the development of constipation. Constipating medications commonly used by older adults include narcotic analgesics; sedatives; hypnotics; antidepressants; anti-cholinergics; some antacids and vitamins that contain calcium, aluminum, or iron; and calcium channel blockers. Laxative use increases with age.” Abuse of stimulant laxatives, in an attempt to regulate bowel activity, was thought to lead paradoxically to worsening symptoms of constipation. However, lack of evidence supporting this view suggests otherwise.

Lifestyle factors that can contribute to or worsen constipation in older adults include failure to establish a schedule for bowel movements; emotional stress; inadequate chewing of foods, which is often a result of poor dentition; a diet that is insufficient in calories and fiber; inadequate fluid intake; and limited exercise. Elderly patients who are sedentary or confined to the bed have an increased risk for developing constipation, because walking has a positive impact on gut peristalsis.

If any of these factors exist, the health care provider should consider lifestyle modifications or an adjustment to current drug therapy before recommending a laxative.

Dietary considerations are especially important in the evaluation of constipation in the elderly. Maintaining a balanced diet with adequate fiber and fluids is important but often difficult to sustain for many older adults. Daily consumption of foods high in fiber or fiber supplements along with six to eight 8-ounce glasses of noncaffeinated, nonalcoholic liquids is recommended. Constipation is often an indication of dehydration in the elderly; therefore, fluid status should be monitored closely.

Chronic laxative use is common among the older population. The aging process can cause the colon to lack normal tone, resulting in an overreliance on oral laxatives or rectal enemas to produce defecation. However, because of the physiologic effects of chronic laxative use on the intestine, laxative dependency is often difficult to manage. Some researchers have found an increased risk for coloretal cancer among laxative abusers. Laxative preparations can also increase the rate at which other drugs pass through the gastrointestinal tract by increasing gastrointestinal mobility, which then decreases absorption and the effectiveness of concurrently administered medications.

Older patients are particularly sensitive to shifts in fluid and electrolytes. Use of any laxative that alters the fluid and electrolyte balance, particularly saline-type laxatives, may be inappropriate in certain patients of advanced age. These laxatives can place older patients, particularly those who are on diuretics or have decreased fluid intake, at risk for adverse effects.

An acute episode of constipation may be treated with plain water or saline enemas. Although not available over the counter, soapsuds enemas and enemas using detergents should be avoided; they can be irritating and can cause serious complications.”" Sodium phosphate and biphosphate enemas are effective but can result in hyperphosphatemia in patients with renal disease.

Bulk-forming agents are generally preferred for older patients who are able to tolerate adequate fluid intake. The onset of effect is usually 12 to 72 hours. Sugar-free products are recommended for patients with diabetes. Adequate fluid intake is necessary with bulk-forming agents to avoid worsening constipation. Glycerin suppositories and the oral administration of lactulose or sorbitol (prescription-only products) are safe and have been used successfully in patients of advanced age. Although considerably more costly than sorbitol, lactulose may be of particular benefit to those who are bedridden, and it is preferred in patients with hepatic encephalopathy. Mineral oil should be avoided in older adults because of the risk of developing lipid pneumonia, particularly in patients who are bedridden. For patients with cardiac and renal disease, PEG-electrolyte solutions. which are poorly absorbed, have been safely used for acute management of constipation.

Some health care providers may recommend chronic stimulant laxatives in certain situations, but these products should not be generally recommended for all older patients. The recommendation to use laxatives in this population should be patient-specific. Older individuals can have complicating pathology, multiple medical complaints, and are vulnerable to the effects of medications. A complete and thorough history should aid in selecting the most appropriate product.

Pregnancy Constipation is common during pregnancy and after childbirth or surgery. It is estimated that one in every three pregnant women experiences constipation during the first and third trimesters. The increasing size of the uterus compresses the colon, affecting the emptying of fecal material. In addition, reduced intestinal muscle tone, which can contribute to a decrease in peristalsis, is likely the primary reason. Other contributing factors in pregnancy include the use of prenatal vitamin and mineral supplements that contain iron and calcium, a decease in dietary fiber and fluid, and a reduction in physical activity. Constipation in pregnancy can lead to backaches, hemorrhoids, and fecal impaction.

The main goal of treatment of constipation in pregnancy is to achieve soft stools without the use of laxatives. Dietary measures that include natural remedies such as prunes or prune juice should be attempted as an initial measure in most patients. However, laxatives may be necessary postpartum in some women to reestablish normal bowel function that was lost because of perinea! pain. Other indications for laxative use may include ileus secondary to colonic dilatation in a decompressed abdomen, laxness of the anal sphincter and abdominal musculature, low fluid intake, hemorrhoids, and administration of enemas during labor. Consultation with a woman’s health care provider is recommended prior to laxative use in more severe cases and when the safety of certain laxative products is questionable.

Because of the potential for adverse effects of several products, such as (1) decreased vitamin absorption caused by mineral oil, (2) premature labor brought on by the irritant effects of castor oil, or (3) possible dangerous electrolyte imbalances with osmotic agents, pregnant women should be very selective in choosing a laxative. Bulk-forming laxatives are the common first-line choice in pregnancy because of their safety and effectiveness. These products require liberal amounts of fluid intake. Usual recommendations are at least 1500 mL/day. If bulk-forming laxatives are ineffective or intolerable, an emollient, senna, or bisacodyl may relieve symptoms. Senna and bisacodyl have also been used safely during breast-feeding. Senna and bisacodyl have not been shown to be present in significant concentrations in breast milk, or no data are available to suggest that infants may experience any potential toxicity. If these products are used, the infant should be carefully observed for diarrhea. Saline cathartics should be avoided during pregnancy and lactation, because appreciable gastrointestinal absorption can occur in the mother. Toxicity occurring from excessive use of a saline cathartic such as magnesium sulfate could be significant, resulting in diarrhea, drowsiness, respiratory difficulty, and hypotonia. These products may promote sodium retention and edema. Pregnant patients who are suspected of using these products should be monitored for increases in serum sodium and weight gain.