UTILITY OF HYDROGEN AND METHANE BREATH TESTS IN COMBINATION WITH X-RAY-EXAMINATION AFTER A BARIUM MEAL IN THE DIAGNOSIS OF SMALL-BOWEL BACTERIAL OVERGROWTH AFTER JEJUNOILEAL BYPASS FOR MORBID-OBESITY

To study why the symptoms of abdominal bloating occurring in a number of patients after jejuno-ileal bypass for morbid obesity become resist ant to antibiotics, we used a method which combined a hydrogen breath test after lactulose with an X-ray examination of the abdomen after ba rium. Ten operated patients with bloating symptoms resistant to antibi otics, ten operated patients without symptoms or with pre-existing sym ptoms, that had remitted after antibiotic treatment and ten non-operat ed obese controls were investigated. There was a significant correlati on between post-surgical symptoms persisting after antibiotics and the exhalation of large amounts of hydrogen of colonic origin (>100 parts per million) after lactulose. Furthermore, symptomatic patients had h igh prevalence of colonic motility disorders (slow transit). In these patients, treatment with a prokinetic (cisapride 40 mg/kg//day for 10 days) reduced colonic transit time, colonic hydrogen production and bl oating symptoms. Abdominal symptoms in these patients may therefore ha ve other causes than small-bowel bacterial overgrowth alone. All opera ted patients with persistent abdominal bloating should therefore be in vestigated before starting empirical treatment with antibiotics.