LARGE-SCALE AMBULATORY STUDY OF POSTPRANDIAL JEJUNAL MOTILITY IN IRRITABLE-BOWEL-SYNDROME

Background: The relationship of small-bowel dysmotility to dietary int ake in irritable bowel syndrome (IBS) is obscure. Methods: This study evaluated postprandial jejunal motility in IBS patients classified as constipation-predominant (n = 25) or diarrhoea-predominant (n = 35) an d compared results against 18 volunteers. Twenty-four-hour ambulatory jejunal manometry was carried out in all subjects, and recordings were analysed by microcomputer and visual assessment. Results: By means of analysis of variance (fitting factors for channels, meals, and time p eriods) postprandial contraction frequency was greater in both patient groups compared with normal (constipation-predominant versus normal, diarrhoea-predominant versus normal; P < 0.001). In the constipation-p redominant cohort, contraction amplitudes were lower (constipation-pre dominant versus normal; P < 0.002). Discrete cluster contractions occu rred with similar frequency and duration in both patient and volunteer groups. Conclusions: Quantitative differences of postprandial jejunal contraction characteristics have been shown between patients with IBS and healthy volunteers. Contraction frequency is greater than normal in both diarrhoea- and constipation-predominant categories, whereas co ntraction amplitudes are lower in constipation-predominant patients.