Chronic Intestinal Pseudo-Obstruction Is Associated with Intestinal Methanogen Overgrowth

Background Chronic intestinal pseudo-obstruction (CIP) is a rare motility disorder characterized by dilated small bowel in the absence of mechanical obstruction. CIP has a known association with small intestinal bacterial overgrowth (SIBO); however, data regarding association with specific subtypes such as methane-positive (M+) and hydrogen-positive (H+) SIBO are limited. Therefore, we conducted this study to characterize subtypes of SIBO in CIP and compare them with non-CIP patients. Aims The aim is to explore the association and prevalence of hydrogen and methane subtypes of SIBO in patients with CIP. Methods A retrospective chart review was conducted for 494 patients who underwent glucose breath tests (GBT) in 2019. CIP was diagnosed based on clinical suspicion and after ruling out mechanical obstruction. We also reviewed demographic data, including age, gender, body mass index, tobacco and alcohol history, medical comorbidities, use of proton pump inhibitors, and history of colectomy. Results Among 494 patients, 7.7% (38) had CIP. The prevalence of M+ GBT in CIP patients was higher compared with non-CIP patients, and it was significant [52.6% (20/38) versus 11.8% (54/456), p < 0.001]. The prevalence of H+ GBT in our cohort of CIP patients was similar to that of non-CIP patients [23.7% (9/38) versus 25.7% (117/456), p = 0.941]. Conclusion The prevalence of methane-positive GBT was higher in CIP patients than in patients without CIP. This finding further strengthens the hypothesis that the relationship between motility disorders and methanogen overgrowth is facilitative.