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.