Published online Apr 15, 2002. doi: 10.3748/wjg.v8.i2.382
Revised: November 7, 2001
Accepted: November 15, 2001
Published online: April 15, 2002
AIM: To assess the diagnostic value of a combination of continuous intragastric pH and bilirubin monitoring in the detection of duodenogastric reflux (DGR), and the effects of diet on the bilirubin absorbance.
METHODS: 30 healthy volunteers were divided into two groups: standard diet group (Group 1) 18 cases, free diet group (Group 2) 12 cases. Each subjects were subjected to simultaneous 24 h intragastric pH and spectrophotometric bilirubin concentration monitoring (Bilitec 2000).
RESULTS: There was no difference of preprandial phase bilirubin absorbance between two groups. The absorbance of postprandial phase was significantly increased in group 2 than group 1. There was no difference between preprandial phase and postprandial phase absorbance in group 1. Postprandial phase absorbance was significantly higher in group 2. In a comparison of bile reflux with intragastric pH during night time, there were 4 types of reflux: Simultaneous increase in absorbance and pH in only 19.6%, increase in bilirubin with unchanged pH 33.3%, pH increase with unchanged absorbance 36.3%, and both unchanged in 10.8%. Linear regression analysis showed no correlation between percentage total time of pH < 4 and percentage total time of absorbance > 0.14, r = 0.068, P < 0.05.
CONCLUSION: Because of the dietary effect, high absorbance fluids or foods should be avoided in detection. Intragastric pH and bilirubin monitoring separately predict the presence of duodenal (and/or pancreatic) reflux and bile reflux. They can not substitute for each other. The detection of DGR is improved if the two parameters are combined simultaneously.