The role of 24-hr gastric pH-monitoring in the interpretation of 24-hr gastric bile monitoring for duodenogastric reflux.

BACKGROUND/AIMS: Duodenogastric reflux is a physiologic phenomenon. For a number of years, alkalinization of the acidic intragastric pH environment, as assessed by 24-hour gastric pH-monitoring, was thought to be caused by duodenogastric reflux. The recent introduction of the fotooptic Bilitec system for intraluminal bilirubin measurement has created the possibility to directly quantify a component of duodenal juice.

METHODOLOGY

In this study, 24-hour gastric pH-monitoring and 24-hour bilirubin monitoring were performed in healthy subjects. The upper limits for physiologic bile reflux are the percentage of total time of bile reflux of 28.2% and an average absorbance during a reflux episode of 0.62 (95th percentile with threshold 0.25).

RESULTS

Comparing bile with pH-monitoring (absorbance > 0.25 and/or pH > 4), an increase of bilirubin was found most frequently with constant pH (43%) or an increase of pH with constant bilirubin (37%).

CONCLUSIONS

The hypothesis was drawn that the composition of duodenogastric refluxate can vary. Bile and pancreatic juice may separately contribute to duodenogastric reflux.