Ambulatory 24-hour jejunal motility in diarrhea-predominant irritable bowel syndrome.

BACKGROUND

Whether small-bowel motility is abnormal in the irritable bowel syndrome (IBS) is a controversy at present. The aim of our study was to compare ambulatory long-term jejunal motility in 35 IBS patients with predominant diarrhea to normal values obtained in 50 healthy controls.

METHODS

Twenty-four-hour motility was recorded in the proximal jejunum with a portable datalogger and tube-mounted miniature pressure sensors. Fasting motility in the waking (W) and sleeping (S) state and the motor response to a standardized evening meal of 600 kcal underwent visual and computer-aided analysis.

RESULTS

Fasting motility in patients showed migrating motor complex (MMC) cycles of normal length and composition. Uninterrupted runs of discrete clustered contractions during phase II (W) occurred in 57% of patients and 52% of controls but had a significantly longer duration in patients (33 +/- 5 versus 19 +/- 7 min; p < 0.005). During phase II (W) IBS patients had an increase in aborally propagated contractions (41 +/- 2% versus 35 +/- 2%; p < 0.01) and higher contraction amplitudes (26.3 +/- 0.8 versus 23.0 +/- 0.5 mm Hg; p < 0.01). Similar differences were obtained during postprandial motility (47 +/- 3% versus 39 +/- 3%; p < 0.01, and 25.9 +/- 0.9 versus 23.8 +/- 0.05 mm Hg; p < 0.02). In three patients (8.6%) disturbed aboral migration of phase III and irregular burst activity, manometric features of chronic idiopathic intestinal pseudo-obstruction, were identified. Whereas 57% of patients had an entirely normal 24-h manometry, 43% had at least one finding not present in any healthy control.

CONCLUSION

Small-intestinal motility is frequently but not universally abnormal in diarrhea-predominant IBS. The abnormal manometric findings are heterogeneous and range from subtle quantitative changes to severe qualitative abnormalities resembling chronic idiopathic intestinal pseudo-obstruction in a small subset of patients.