Motility abnormalities in irritable bowel syndrome.

Background/aims: The intestinal pathophysiology in irritable bowel syndrome (IBS) is largely unknown. The lactulose breath test has been used to identify small bowel bacterial overgrowth in these patients.

Methods: We studied intestinal transit in patients with IBS using of the SmartPill® (SP) wireless pH/pressure recording capsule and performed lactulose breath tests to look for physiologic abnormalities.

Results: A total of 35/46 (76%) of the IBS patients had prolonged gastric emptying times. Constipation-predominant disease was associated with prolonged gut transit times. The mean hours ± SD for colonic transit time in the constipation group was 71.7 ± 61.1 (n = 13) compared with 22.5 ± 14.9 (n = 14) for diarrhea-predominant and 26.4 ± 21.5 (n = 20) for mixed clinical subtype (p = 0.0010). No correlation between small bowel transit time and abnormal breath hydrogen or methane excretion in the 46 combined patients with IBS was seen.

Conclusions: Delayed gastric emptying was identified in IBS and in some patients may contribute to at least a component of their symptoms. Constipation-predominant IBS is associated with prolonged gut transit times. Otherwise, transit abnormalities do not appear to be important in IBS. Intestinal transit did not correlate with breath test results.