CARBACHOL STIMULATION OF GASTROINTESTINAL TRANSIT IN THE POST-OPERATIVE ILEUS RAT

Postoperative ileus was studied in a rat model which allowed simultaneous and quantitative measurement of gastric emptying (GE), small intestinal transit (SIT), and colonic transit (CT). Measurement of CT for the first time in an animal ileus model was made possible by the injection of solidified, ink-stained agar into the proximal colon. Methoxyflurane and Cyclopal anesthesia were found to delay GE. Abdominal skin incision, but not dorsal skin incision, decreased SIT. Laparotomy caused maximal decrease in GE, SIT, and CT, but laparotomy coupled with intestinal manipulations slowed the spontaneous recovery of the small intestine. The colon regained normal propulsion 9 hr after surgery, followed by the small intestine (12 hr), and then the stomach (18 hr). Carbachol given before or after surgery increased propulsive ability of all three organs, normalizing GE and CT, but not SIT. The rat appears to be an appropriate model for studying postoperative ileus if care is taken to measure transit in each part of the gastrointestinal tract with separate transit markers. The stomach, small intestine, and colon respond differently to various conditions and possibly have dissimilar neuronal inputs controlling propulsion. © 1979.