title: Assessment of duodenogastric reflux by combined continuous intragastric pH and bilirubin monitoring.
abstract: OBJECTIVE
  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-hour 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Gastroenterology, Second Hospital of Xi'an Jiaotong University, 157 Xiwu LU, Xi'an 710004, Shaanxi Province, China. jiangdf@pub.xaonline.com
authors.forename: Fei
authors.initials: F
authors.lastname: Dai
authors.forename: Jun
authors.initials: J
authors.lastname: Gong
authors.forename: Ru
authors.initials: R
authors.lastname: Zhang
authors.forename: Jin-Yan
authors.initials: JY
authors.lastname: Luo
authors.forename: You-Ling
authors.initials: YL
authors.lastname: Zhu
authors.forename: Xue-Qin
authors.initials: XQ
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D001663:Bilirubin / Q000378:metabolism*; D004032:Diet; D004383:Duodenogastric Reflux / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D005336:Fiber Optic Technology / Q000295:instrumentation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D011897:Random Allocation
chemical_list: D001663:Bilirubin