Stimulation of the small intestine by nutrients in relation to phase of the migrating motor complex

Background: The relationship between the preceding phase of the migrating m otor complex (MMC) and postprandial motility in the small intestine was stu died. Methods: In eight healthy subjects small-bowel manometry was performe d, and a 55-ml caloric liquid bolus (250 kJ) containing paracetamol and C-1 4-D-xylose was instilled into the duodenum during phase I and late phase II of the intestinal MMC, respectively, in randomized order. Blood samples we re drawn at regular intervals and analysed for insulin, gastrin, glucose, p aracetamol, and C-14-D-xylose. Results: After bolus administration during l ate phase Il a phase-III-like activity succeeded by quiescence occurred in the duodenum in seven of eight subjects, whereas administration during phas e I initiated irregular contractions in seven of eight subjects (P < 0.05). The caloric bolus induced a significant increase in serum insulin and gast rin. Areas under the curves for serum insulin. gastrin, glucose, paracetamo l, and C-14-D-xylose were not modulated by the preceding phase of the MMC. Conclusions: The present study shows that a nutrient bolus instilled into t he intestinal lumen induces MMC-like activity when administered during late phase ii. These findings provide further evidence of interference between MMC and postprandial motility.