Metano no ar expirado de crianças com constipação crônica funcional / Breath methane in children with chronic constipation

ABSTRACT

Methane is an intestinal gas which may be excreted in the expired air of about 10% of children. OBJECTIVE: The aims of this study were to investigate methane production by children with functional chronic constipation and methane concentration in the expired air before and after a bowel movement induced by a phosphate enema. METHODS: Seventy-five patients with functional chronic constipation aged from 3 to 13 years were studied. Methane concentration in the expired air was determined using a gas chromatograph (Quintron, model 12i). Methane production was considered present if the breath methane concentration was equal or greater than 3 ppm. RESULTS: Methane production was present in 44 (86.3%) of 51 patients with constipation and fecal soiling versus only 7 (29.2%) of 24 patients with constipation without fecal soiling. After six weeks of therapy for constipation, the number of methane producers decreased by 65.2%. None of the 10 children with normal intestinal habit produced methane. Expired air methane concentration was determined before and after a bowel movement induced by a phosphate enema in 20 patients with impacted stool. From these 20 patients, 12 were methane producers. The median (percentiles 25 and 75 between parenthesis) of methane concentration decreased from 21.5 (15.0-25.5) ppm before to 11.0 (4.0-12.5) ppm after the bowel movement. CONCLUSION: Methane production was associated with chronic constipation with soiling and decreased when impacted stool decreased