title: Gastric bile monitoring: an in vivo and in vitro study of Bilitec reliability.
abstract: BACKGROUND
  It has been claimed that the combination of bile and hydrochloride acid (HCl) has a noxious effect on intestinal mucosa. The aim was to study the reliability of the Bilitec 2001 method inmonitoring the presence of bile in repeated tests and at different pH and water dilutions.
  
  
  METHODS
  24-h esophageal pH and gastric Bilitec monitoring were performed twice with an interval of 6 weeks in 23 patients with symptomatic gastroesophageal reflux (GER). In vitro tests of pH and Bilitec recordings were peformed with different mixtures of bile, HCl and water.
  
  
  RESULTS
  Gastric bile was present in 37% of the recording time, 28% during day time and 47% during nights. No significant difference was found between the two test occasions. The maximum bile concentration in the stomach was significantly lower in patients with severe pathological GER than in those with normal GER. When concentrated bile was diluted with the same volume of HCl, the pH level fell below 4. The maximum absorption limit with Bilitec in concentrated bile was gradually reduced with decreasing pH. The Bilitec technique recorded the presence of bile even at a pH of 1.4, but not if the bile was diluted with water at a ratio of 1:100 or more.
  
  
  CONCLUSIONS
  Bilitec gastric recordings show the same clinical result when repeated under standardized conditions. The Bilitec technique is not reliable for monitoring the amount and concentration of bile in the stomach. Bile reflux cannot be monitored with the pH recording technique.
authors.affiliation: Dept. of Surgery, University Hospital, Linköping, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Tibbling Grahn
authors.forename: L
authors.initials: L
authors.lastname: Blackadder
authors.forename: T
authors.initials: T
authors.lastname: Franzén
authors.forename: E
authors.initials: E
authors.lastname: Kullman
mesh_terms: D000328:Adult; D000368:Aged; D001646:Bile / Q000502:physiology*; D001655:Bile Reflux / Q000175:diagnosis / Q000503:physiopathology; D001663:Bilirubin / Q000032:analysis; D003938:Diagnostic Techniques, Digestive System / Q000295:instrumentation*; D004383:Duodenogastric Reflux / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D005750:Gastric Juice / Q000737:chemistry* / Q000502:physiology; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000503:physiopathology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D008991:Monitoring, Physiologic / Q000379:methods; D015203:Reproducibility of Results; D013053:Spectrophotometry / Q000295:instrumentation / Q000592:standards
chemical_list: D001663:Bilirubin