Regulation of postprandial motility in the canine ileum.

We describe here further observations on a novel motor phenomenon that can be recorded regularly from the canine ileum in the late postprandial period, i.e., when residue of a meal reaches the distal small bowel. We reported before that this unique pattern of motility consisted of intraluminal pressure waves at a frequency (20-24/min) much greater than that of the ileal slow wave. In the current experiments, we document that these intraluminal pressure waves coincide with contraction of the circular muscle layer, as recorded from serosal strain gauges. However, the cellular origin and propagation of these contractile events are still unclear. By studying dogs with ileal loops and those with an intact bowel, we conclude that this is a local response of the ileum to the arrival of nutrients in its lumen and that it is under cholinergic control. This report supports the concept that the ileum may be particularly sensitive to its local intraluminal environment.