Bacterial overgrowth and methane production in children with encopresis.

OBJECTIVES: To assess the prevalence of small intestinal bacterial overgrowth (SIBO) and methane production in children with encopresis. STUDY DESIGN: Radiographic fecal impaction (FI) scores were assessed in children with secondary, retentive encopresis and compared with the breath test results. Breath tests with hypoosmotic lactulose solution were performed in both the study patients (n = 50) and gastrointestinal control subjects (n = 39) groups. RESULTS: The FI scores were significantly higher in the patients with encopresis who were methane producers (P < .01). SIBO was diagnosed in 21 of 50 (42%) patients with encopresis and 9 of 39 (23%) of control subjects (P = .06). Methane was produced in 56% of the patients with encopresis versus 23.1% of the control subjects in the gastrointestinal group (P < .01). Fasting methane level was elevated in 48% versus 10.3 %, respectively (P < .01). CONCLUSIONS: Children with FI and encopresis had a higher prevalence of SIBO, elevated basal methane levels, and higher methane production. Methane production was associated with more severe colonic impaction. Further study is needed to determine whether methane production is a primary or secondary factor in the pathogenesis of SIBO and encopresis.

Breath methane production in children with constipation and encopresis.

Breath methane excretion is uncommon in children compared with adults. Certain intracolonic conditions, however, have been associated with enhanced methane generation. We hypothesized that encopretic and constipated children, who have abnormal colonic transit times, more likely would excrete methane than healthy children. To determine the prevalence of methane excretion among children with encopresis or simple constipation, we performed breath methane analysis on such patients and age-, race-, and sex-matched control subjects. Encopretic patients (mean age, 8.3 +/- 3.0 years) had daily, involuntary passage of feces and clinical evidence of constipation. Constipated patients (mean age, 7.1 +/- 2.9 years) had a history of hard stools and at least one of the following symptoms: infrequent defecation, dyschezia, hematochezia, difficult stool expulsion, or abdominal pain during bowel movements. Methane excretion was present in 26 of 40 (65%) encopretic patients versus 6 of 40 (15%) control patients (P less than 0.001). In contrast, 3 of 27 (11%) constipated patients were methane excreters, versus 2 of 27 (7%) controls (P = 0.4). Fourteen asymptomatic encopretic patients were retested after successful therapy; eight were methane excreters initially, but five of eight did not excrete methane after treatment. We conclude that methane is produced in a large number of children with encopresis. Treatment appears to alter methanogenesis in such patients. The prevalence of methane producers among constipated children is not different from the prevalence in healthy subjects. Methanogenesis in encopretic patients may be enhanced by prolonged colonic transit time or abnormal intracolonic conditions.