What is constipation?

Constipation is the final link in a chain of functional disturbances or disease processes. Defecation requires that the stimuli sent by the nervous system (vagus nerve) to the large intestine function properly. This depends on the unimpaired activity of the muscles of the large intestine and the pelvis and the activity of the nerve cells in the large intestine (plexus myentericus). If just one of these components is impaired, the transport of the intestinal contents will be slowed down or the pelvic muscles will not be properly co-ordinated. This in turn leads to reduced or increased stool frequency.

How often is normal?

100 – 150 g of stools per day with a frequency of 3 times a day to 3 times a week is considered normal. We refer to constipation in the case of delayed bowel movements (fewer than 3 times a week) of unusually hard and dry stools with a water content of less than 80 percent.

Not every case of perceived ‘constipation‘ needs treatment. The person concerned is often unaware that the frequency of stools, the volume of stools and the consistency of the stools depends on their lifestyle, age, gender and can fluctuate considerably depending on the present situation.

It is important to point out that a person may only perceive that they are constipated if they believe that bowel movements are required every day with the result that failure to pass stools on one day leaves them with the feeling they are constipated.

Only a quarter of constipated persons actually have an excessively low stool frequency. Most people tend to complain, however, of too little volume, severe straining during defecation, and excessively hard stools, accompanied by stomach pains and flatulence.

Signs of constipation

Factors causing constipation

Many worldwide representative surveys reveal that frequency of constipation is highly correlated with age and gender. But independent from these factors there are important others:

Constipation can be caused by several factors including:

• A poorly balanced diet
• A low-fibre diet
• Insufficent fluid intake
• A lack of exercise
• Intake of certain medications
• Changes in routine, like holidays
• Change of metabolism
• Suppressing the urge to go to the toilet
• Stress
• After operations
• Organic lesions
• Pregnancy
• Menopause
• Diseases
• etc.

As we grow older, our bowel muscles can become less active as our metabolism slows down and constipation can become an increasing problem. At this time it is especially important to have a healthy diet, regular exercise and sufficient fluid intake.

Causes of Constipation

Constipation is either due to delayed intestinal transit with severe dehydration or to disturbances of the defecation reflex.

Functional disturbances (disturbed intestinal nerve function, irritable bowel syndrome) are usually at the root of the problem. In 10 to 20 percent of cases, however, constipation can be due to organic problems (chronic intestinal inflammation, tumours, haemorrhoids, anal fissures, and inadequate pelvic muscle activity).

Delayed intestinal transit

Disturbances of spontaneous activity are presumably the most common cause of large intestinal complaints. Constipated persons, when compared with non-sufferers, have often been found to show delayed intestinal transport. Constipation with delayed intestinal transit often goes hand in hand with a disturbance of the nerve plexus in the intestinal wall or neurological disease. General disturbances of the sensitivity of the nerve endings lead to changes in the gastrointestinal tract affecting the reflex system that triggers bowel movements. The result is impaired intestinal motility. In patients with this type of complaint, usually women, treatment with laxatives that do not stimulate the spontaneous activity of the large intestine, for instance bulking agents may often be insufficient. Treatment with these products will have no effect.

brain
afferent nerve fibers
efferent nerve fibers
transmitting substance acetylcholinen
receptorn
ganglion
smooth muscles

Types of constipation