Canine gastric emptying of polycarbophil: an indigestible, particulate substance.

We tested whether indigestible solids could empty from the canine stomach independently of gastric burst motor activity. Test meals contained polycarbophil, an indigestible particulate (1-3 mm diameter) substance. Test meals were slurries of 30 or 90 g of radiolabeled polycarbophil particles in saline. Meals were administered via an oral gastric tube. After 4 h, the stomach was drained via a gastric cannula, and the percentage of meal that had emptied into the duodenum was calculated. Antroduodenal motor responses to the meals were monitored with strain-gage force transducers. The motor responses to polycarbophil meals were compared with those after canned food and saline meals. Fifty percent of the 90-g polycarbophil meal emptied by 4 h; this occurred independently of gastric burst motor activity. Both polycarbophil and canned food elicited similar indexed motor responses and both delayed the postprandial reappearance of gastric burst motor activity. We conclude that small indigestible particles can stimulate fed state-like motility and empty from the stomach independently of gastric burst activity.