Study on gastrointestinal motility mechanism of duodenogastric reflux

Background: Duodenogastric reflux (DGR) is a common physiological and pathological phenomenon, which is related to the development of many diseases. However, its mechanism remains unclear. Aims: To appraise the relationship between DGR and interdigestive antroduodenal migrating motor complex (MMC). Methods: Simultaneous 24-hour intragastric pH and Bilitec monitoring, and a long duration overnight antroduodenal manometry were carried out in 20 healthy volunteers. Results: After simultaneous 24-hour intragastric pH and Bilitec monitoring, 20 healthy volunteers were divided into two groups: DGR-negative (D1) group (n=7) and DGR-positive (D2) group (n=13). The number of MMC was significantly increased in D1 group (P<0.05), whereas the antroduodenal coordinated contractions and duodenal propagated contractions were significantly decreased in D2 group (P<0.05, respectively). The incidence of duodenal MMC phase III retroperistalsis in D1 group decreased markedly than that in D2 group (P<0.05). In D2 group, the mean values of intragastric pH 10 minutes before and after MMC phase III retroperistalsis were 1.72±0.61 and 3.70±0.72, respectively, the difference was statistically significant (P<0.01). The incidences of overnight alkaline reflux and bile reflux in MMC late phase II were significantly higher than those in phase I , early phase II and phase III (P<0.05, respectively). Conclusions: The occurrence of DGR is related to the number of antroduodenal MMC, late phase II and retroperistalsis of phase III.