MILWAUKEE — Regular enemas did not reverse increased rectal compliance in children with intractable functional constipation, Dr. Marc Benninga reported at an international symposium sponsored by the International Foundation for Functional Gastrointestinal Disorders.
The prospective, longitudinal barostat study of 101 patients also found that increased rectal compliance was not related to treatment failure.
Rectal compliance is an indirect measure of contraction and relaxation in the rectum. It is thought to be increased in children with constipation compared with healthy children, and to be reduced in those with irritable bowel syndrome with diarrhea.
Regarding the result that enemas did not reverse increased rectal compliance, Dr. Benninga said: “It is a provocative finding, because increased rectal compliance seems not to be an important underlying mechanism of intractable functional constipation in childhood.” Dr. Benninga works in the department of pediatric gastroenterology and nutrition at Emma Children's Hospital/Academic Medical Center, University of Amsterdam.
The study was enthusiastically received by audience members. “Your study required a lot of work and a lot of courage,” said Dr. David R. Fleischer of the department of child health at the University of Missouri in Columbia. “It deflates a lot of the pediatric folklore that has led to iatrogenic abuse of children.”
The investigators randomized 101 children aged 8–18 years, with symptoms of functional constipation lasting for at least 2 years, to either conventional treatment with laxatives and toilet training or conventional treatment plus enemas. Patients in the latter group had three enemas per week for the first 3 months, with a reduction in the number of enemas by one per week every 3 months.
Among the 87 children who completed 12 months of treatment, there were no significant differences in clinical success between the two treatments or between children with and without abnormal rectal compliance at baseline.
Functional constipation was defined as the presence of two or more of the following criteria: defecation frequency less than three times a week, fecal incontinence at least twice a week, large-diameter stool, and fecal retention at physical examination.
The patients' mean age was 11 years, 65% were boys, 72% had large-diameter stools, and 47% had fecal impaction. Defecation frequency averaged 1.5 per week, and fecal incontinence occurred an average of seven times per week. Symptom duration averaged 7 years.
Assessment of rectal compliance was performed with an electronic barostat and polyethylene bag, which is thought to be more accurate than a latex balloon and manual inflations used in clinical settings, Dr. Benninga explained. The upper limit of the normal range was 20 mL/mm Hg.
Clinical success, defined as defecation at least three times per week and fecal incontinence less than once a week, was achieved in 33 children with normal rectal compliance, 34 with moderately increased compliance, and 20 with severely increased compliance, Dr. Benninga said at the meeting, which was cosponsored by the University of Wisconsin.