Vera Loening-Baucke, MD, Professor,
Department of Pediatrics, University of Iowa.
John is an eight-year-old boy whose
parents have brought him to see you for an evaluation of fecal soiling. His
parents explain that he has never been fully toilet trained. Soiling occurs
daily and consists of small bowel movements in his underwear. His bowel movements
are soft to firm in consistency, often large but never having clogged the toilet.
John denies any sensation of the need to have a bowel movement. He is not having
abdominal pain, nor is urinary incontinence a problem for him.
Functional constipation and encopresis.
About 2% of all children experience fecal soiling. For 95% of these children, soiling is due to functional constipation, and is called encopresis. Functional constipation is not caused by medication, nor by organic disease.
In children, constipation is defined as any of the following:
- Stool frequency of fewer than three bowel movements per week.
- Passage of painful bowel movements often accompanied by severe discomfort.
- Stool retention with or without encopresis, even when bowel movements occur more often than three times per week.
No single mechanism is responsible for functional constipation; slow motility, psychological factors, and painful defecation may all be factors.
Encopresis is a repeated, involuntary passage of feces into the underwear that occurs at least once a month over a period of at least 6 months. The chronologic and mental age of the child must be at least 4 years. Physical disorders that can cause fecal soiling must be ruled out. Boys are more likely than girls to present with this condition, with the male to female ratio for encopresis being about 3 to 1.
When a child presents with apparent encopresis, determine the intervals, size, and consistency of bowel movements deposited into the toilet and into the underwear. Gathering information about the age of onset of symptoms and about the child's dietary history. Some children with encopresis have daily bowel movements but evacuate incompletely, as evidenced by the periodic passage of very large amounts of stool, sometimes large enough to clog the toilet.
The size, consistency and frequency of soiling will vary among children, as well as for a given child. Soiling may occur occasionally, once a day, or many times a day. The consistency of the stools found in the underwear is usually loose or clay-like. Sometimes the core of the impaction breaks off and is found as a firm stool in the underwear. About half of all children with encopresis complain of abdominal pain. Additional complaints in patients more than five years old are:
- Daytime urinary incontinence - 27%.
- Bed wetting - 32%.
- Current or past history of urinary tract infection - 3% of boys and 42% of girls.
Children with encopresis will often deny the presence of stool in their underwear, and the accompanying foul and
penetrating odor. Many children hide their soiled underwear. Parents usually find this situation very frustrating, and soiling becomes a major issue of contention between parents and child. Parents often assume that the encopresis is caused by the reluctance of the child to use the toilet, and it is important for parents to understand that encopresis is involuntary.
Physical examination should be complete, with special emphasis directed to weight, height, body configuration, and to abdominal, rectal, and neurologic examination.
An abdominal fecal mass can be palpated in about half of all children with encopresis. Sometimes the mass extends throughout the entire colon, but it is more commonly felt suprapubically and midline, sometimes filling the left or the right lower quadrant. Inspect the anus; notice soiling, scarring, the location of the anus, a patulous anus, and the anal reflex contraction to pin prick or stroking of the anal skin.
During digital examination of the rectum, assess the basal anal tone, the length of the anal canal, the size of the rectum, and the rectal content. Examination may reveal a rectum packed with stool, either of hard consistency or, more commonly, with the outside of the fecal impaction like clay and the core of the impaction rock hard. Sometimes the retained stool is soft to loose.
After you have taken a careful history and completed a physical examination, including a rectal digital examination, you will be ready to decide whether further work-ups, such as blood studies, x-ray studies, anorectal manometric studies, or rectal biopsy, are required. Functional tests and radiologic examinations, however, can never be a substitute for a carefully gathered case history and physical examination.
Treatment consists of:
- Maintenance treatment.
- Prevention of stool reaccumulation.
- Reconditioning to normal bowel habits.
- Withdrawal of medication.
Parents are encouraged to give several servings daily from a variety of fiber-rich foods. Defecation trials are a must in any treatment program. The child is encouraged to sit on the toilet for up to five minutes, three to four times a day, following meals. We use positive reinforcement for toilet use in children with previous toilet refusal.
For most patients with constipation, the daily administration of laxatives, such as milk of magnesia or sorbitol, promotes daily defecation. Laxatives should be used according to age, body weight, and severity of constipation. If stool softeners and laxatives are ineffective in the initial treatment of patients with megacolon or megarectum, then 5-15 ml Senekot or a 10-mg bisacodyl suppository daily will help to stimulate defecation. (Mineral oil should not be used for young children, or for children who have difficulty swallowing, due to the risk of aspiration.)
When regular bowel habits are established for some time, gradually decrease medication. Continue to withdraw laxatives so long as soiling and stool retention do not reappear. Resume treatment if soiling recurs. Medications often need to be continued for several months, sometimes years. Stopping the laxative too soon is the most common cause for relapse.
For further reading
Loening-Baucke V. (1996) "Encopresis and soiling." Pediatric Clinics of North America 43: 279-298.
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