A study on antro-duodenal motility in irritable bowel syndrome

Objective To investigate the variety of antro duodenal motility in patients with diarrhea or constipation predominant irritable bowel syndrome (IBS) and to elucidate the pathophysiology of IBS. Methods After 6 hours fasting, 17 patients with IBS (diagnosed by Rome Ⅱ criteria), 8 with diarrhea predominant diarrhea(D IBS) and 9 with constipation predominant IBS(C IBS), were investigated by gastrointestinal manometry (STD Co., Sweden) for recording at least 2 intergrated interdigestive migrating motor complex (MMC) cycles and observing 2 hours of postprandial antro duodenal motility. Results The MMC periods was shorter, phase Ⅲ duration was longer and amplitude was higher in D IBS group than in controls, whereas the MMC periods was longer and the phase Ⅲ duration was shorter in C IBS group than in controls. The duration of discrete clustered contraction(DCC) in phase Ⅱ was longer in IBS groups than in health controls, but there was no significant difference between the C IBS group and the D IBS group. The motility index in late phase Ⅱ and phase Ⅲ was higher in IBS D group, but for the IBS C group the motility index had no statistical difference from that for controls. The postprandial motility pattern of duodenum had no remarkable difference between IBS patients and controls. Conclusions The gastrointestinal motility disorders are apparent in the IBS patients. There is close relation between gastrointestinal motility disorders and the symptoms of the IBS patients. DCCs waves may almost be independent of constipation or diarrhea of IBS.