Large-scale ambulatory study of postprandial jejunal motility in irritable bowel syndrome.

BACKGROUND

The relationship of small-bowel dysmotility to dietary intake 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) and 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 periods) 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-predominant cohort, contraction amplitudes were lower (constipation-predominant versus normal; P < 0.002). Discrete cluster contractions occurred 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 contraction amplitudes are lower in constipation-predominant patients.