Methane production may be directly relatedto colonic transit time. To analyze this relationship,Ana Soares, MD, PhD, and colleaguesconducted a study (reported in the Journal ofClinical Gastroenterology, July 2005) of 40children aged 3 to 13 years with chronic constipation.Using radiopaque markers, total andsegmental colonic transit times were measured.Soiling (associated with methane productionin pediatric patients) occurred in 34 ofthe 40 patients. Methane was produced in73.5% (25/34) of patients with constipationand soiling and in only 16.7% (1/6) in thosewith constipation but no soiling (P = .014).
The median total colonic transit times foreach group were 80.5 and 61.0 hours,respectively (P = .04); ≤62 hours was normal.The segmental colonic transit timeswere 17.5 and 10.5 hours, respectively (P =.580), in the right colon; 29.5 and 10.5 hours(P = .001), respectively, in the left colon; and31.5 and 27.0 hours (P = .202), respectively,in the rectosigmoid (normal values, 10, 10,and 32 hours, respectively). By the sixthweek of treatment (enemas, laxatives, fiber),the number of methane producers decreasedby 65.2% (15/23). Total colonictransit time was reduced by 50.2% innon-methane producers, suggesting thatthe presence of breath methane in childrenwith chronic constipation may be an indicationof prolonged colonic transit time.