Ambulatory Small Intestinal Manometry (Detailed Comparison of Duodenal and Jejunal Motor Activity in Healthy Man)

The aims of this study were to provide adetailed comparison of duodenal and jejunal motoractivity in healthy individuals by utilizing prolongedambulatory manometry in combination with computer-aided analysis. Intraluminal pressure profiles werestudied in the duodenum and jejunum of 18 healthyvolunteers over 24 hr. The subjects ingested two meals,both of 800 kcal and of equal chemical composition, at two different times of the day. Over thewhole interdigestive period, phase III motor activitystarted more frequently distal than proximal to theligament of Treitz. However, an increasing time offasting was linearly related to an increasing number ofphase IIIs originating proximal to the ligament ofTreitz (r = 0.95). Both meals induced a postprandialmotor pattern of similar duration and contractileactivity. As compared to the jejunum, individual duodenalcontractions during the postprandial period and duringphase II had a higher duration and amplitude. Propagatedclustered contractions occurred more frequently in the duodenum than in the jejunum, both inthe interdigestive and digestive state. Jejunal clusterscomprised a higher number of individual contractions oflower amplitude and duration. In healthy man duodenal and jejunal motor activity aredifferent, both in the digestive and interdigestivestate. The differences include the number of activityfronts traversing these segments of the gut, the number and organization of propagated clusteredcontractions, and subtle changes in the amplitude,duration, and coordinated propagation of individualcontractions. These changes presumably reflect aregulatory capability of the small intestine to modulatethe rate of transit of intraluminal contents throughdifferent segments of the gut.