Gastric and duodenal motility in relation to duodenogastric reflux in healthy dogs.

Motility of the antrum, pyloric sphincter, duodenal bulb and proximal duodenum was recorded in unanesthetized dogs. The timing between pyloric and duodenal contractions was imperfect in the interdigestive and also in the digestive state. The duodenal bulb often contracted before the pylorus was completely closed. Duodenogastric reflux occurred occasionally during gastric emptying, during the interdigestive activity and after stimulation of duodenal motility by hydrochloric acid. Reflux was produced by atypical contractions of the duodenal bulb.