Stool incontinence occurs in about 3 to 4% of 4-year-old children and becomes less common as age increases. It occurs most often in conjunction with toilet training or starting school.
The main causes of stool incontinence are
Although it seems to be a contradiction, stool incontinence is usually caused by constipation. Constipation is delay or difficulty in passing stool and can have many causes, particularly behavioral (for example, fear of using the toilet or of passing hard stool) and dietary (for example, not eating enough fiber). But whatever the cause, as stool remains in the bowel, water is absorbed, which hardens the stool. Because it can be painful to pass a large, hard stool, children block the urge to move their bowels even more, resulting in a vicious circle of worsening constipation. The child may not be able to pass the hardened stool, which remains in the rectum (impacted stool). Then, soft, wet stool from higher in the large bowel may leak around the hardened lump of stool, resulting in stool incontinence. If constipation continues, the wall of the rectum and large bowel stretches. Continued stretching reduces the child's sensation that the bowel is full and impairs muscle control, further increasing the risk of stool leakage.
Occasionally, doctors need to test children for a physical cause or disease. Sometimes, psychologic factors may cause stool incontinence.
Doctors base the diagnosis of stool incontinence on the child's history and a physical examination. In older children, doctors may use a gloved finger to gently examine the rectum to gauge sensation and determine whether there is impacted stool. Sometimes doctors do other tests, such as abdominal x-rays, to rule out other causes.
If the cause is constipation, a laxative or other agent is prescribed to completely clean out the bowel, which is a necessary starting point. Once the bowel is cleaned out, which is sometimes confirmed by abdominal x-rays, children begin a regular laxative regimen and a behavior plan to ensure regular bowel movements. After regular bowel movements are achieved, children begin a maintenance phase.
The behavior plan typically includes structured toilet-sitting times, in which children sit on the toilet for 5 to 10 minutes after each meal whether or not they feel the urge to move their bowels. If children have accidents during certain times of the day, they also should sit on the toilet immediately before those times. Small rewards are often useful. For example, giving children stickers to place on a chart each time they sit on the toilet (even if there is no stool production) can increase their desire to follow the plan. Often a stepwise program is used in which children receive small rewards (such as stickers) for sitting on the toilet and larger rewards for consistently following the plan. Rewards may need to be changed over time to maintain children’s interest in the plan.
If the caregiver-initiated behavior plan is unsuccessful, the child may be referred to a behavioral therapist or child psychologist who is experienced in treating children who have stool incontinence. These specialists strongly recommend that caregivers who are frustrated by incontinence and stool-soiling behaviors avoid punishing the child or showing disappointment to the child for a lack of progress or for any regression to old behaviors after progress had been made. Behavioral therapists and child psychologists often also caution caregivers against using too much positive praise.
Once regular bowel movements are achieved, the leakage often stops. Maintaining soft stools for several months can be necessary for the stretched bowel wall to return to normal and for awareness of the sensation of rectal fullness to return. In the maintenance phase, some laxatives and regular toilet-sitting times still are needed to encourage a bowel movement before the sensation to move the bowels is felt.
After this maintenance phase, the dose of laxatives is slowly decreased, then stopped, and the number of regular toilet-sitting times is reduced. This is often the time that relapse occurs, so health care practitioners continue to monitor children.
If these measures fail, diagnostic tests may be done, such as abdominal x-rays and rarely a biopsy of the rectal wall, in which a tissue sample is taken and examined under a microscope. If a physical cause for the constipation is found, it often can be treated. In the most severe cases, psychologic counseling may be needed for children whose stool incontinence is the cause or the result of emotional or behavioral problems.