Scintigraphic Assessment of Interdigestive Duodenogastric Reflux in Humans: Distinguishing between Duodenal and Biliary Reflux Material

Abstract

Background: Late duodenal phase III is characterized by retroperistalsis. The physiologic function of this phenomenon is unknown. Our aim was to study the relationship between duodenal motility and the transport of duodenal contents from the biliary tract and the duodenum by using a double-isotope technique. Methods: Manometric analysis of the direction of interdigestive duodenal pressure waves was performed in 12 volunteers. Duodenal marker was infused directly into the proximal duodenum, and bile marker was infused intravenously for 2 h. Radionuclide activity was examined for regions corresponding to the stomach, gallbladder, and duodenum. Results: In phase II, antegrade pressure waves dominated with propulsion of both markers to the jejunum. Retroperistalsis occurred in 90% of the activity fronts and was always (100%) followed by retropulsion of duodenal marker to the stomach. A clear-cut reflux of bile marker was seen in only 17% of the activity fronts. The incidence rate of duodenogastric reflux was highest in phase III (P = 0.008) compared with phase II with an infrequent (P = 0.002) admixture of bile. Bile marker contents increased abruptly in the gallbladder during phase III. Conclusions: Late phase III acts as a retroperistaltic pump, retropelling duodenal contents to the stomach. In this physiologic duodenogastric reflux, bile is avoided by deviation to the gallbladder, probably by a phase III-associated occlusion of the sphincter Oddi.