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 Jejuno-Ileal 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 resistant to antibiotics, we used a method which combined a hydrogen breath test after lactulose with an X-ray examination of the abdomen after barium. Ten operated patients with bloating symptoms resistant to antibiotics, ten operated patients without symptoms or with pre-existing symptoms, that had remitted after antibiotic treatment and ten nonoperated obese controls were investigated. There was a significant correlation 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 high 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 bloating symptoms. Abdominal symptoms in these patients may therefore have other causes than small bowel bacterial overgrowth alone. All operated patients with persistent abdominal bloating should therefore be investigated before starting empirical treatment with antibiotics.

Intestinal Microflora Settlement in Patients with Jejunoileal Bypass for Morbid Obesity.

Intestinal microflora settlement was evaluated in this retrospective study of 49 patients with jejunoileal bypass who required reoperation. Colonic microflora was observed in the samples of the contents of the functioning jejunum and ileum but not in 55% of the samples from the middle of the excluded loop. Colonization of the excluded loop was not detected in patients without clinical signs of bacterial overgrowth but was significantly frequent (p < 0.01) in those with clinical signs (bloating, migratory arthralgias, rashes, skin lesions). However, positive excluded loop cultures were not always associated with clinical manifestations. No significant correlation was observed between bacteriology of the contents of the excluded loop and bypass results. The success of an intestinal bypass may depend not only on anatomic and functional adaptation to the new, surgically created conditions, but also to the attainment of microbiological equilibrium in the intestinal ecosystem.