title: Do acid and bile reflux into the esophagus simultaneously? Temporal relationship between duodenogastro-esophageal reflux and esophageal pH.
abstract: BACKGROUND
  Duodenogastro-esophageal reflux (DGER) is an important factor in the pathogenesis of reflux esophagitis. Animal studies have demonstrated that the injurious effect of duodenal juice components depends on pH. The purpose of the present study was to investigate the temporal relationship between DGER and esophageal pH.
  
  
  METHODS
  Seventy-six children with symptoms of gastro-esophageal reflux disease (27 without, 31 with mild, 18 with severe esophagitis) underwent 24 h simultaneous esophageal pH and bilirubin monitoring with Bilitec 2000. The recordings were analyzed for (i) pH at the beginning of DGER episodes; (ii) relative duration of DGER in eight defined pH intervals of 1 pH unit; and (iii) differences in relative duration of DGER between the three groups of children.
  
  
  RESULTS
  DGER episodes most frequently began at pH between 6 and 7. DGER was present in the esophagus across the spectrum of esophageal pH, with the biggest relative duration between pH 3 and 5. However, in children without esophagitis relative duration of DGER was longest between pH 5 and 6, in children with mild esophagitis between pH 4 and 5, while in those with severe esophagitis it was between pH 2 and 4 (P < 0.001).
  
  
  CONCLUSIONS
  DGER appears across the whole esophageal pH spectrum. The more severe the esophagitis, the lower the pH at which DGER occurs, resulting in simultaneous damaging effects of acid and duodenal juice components.
authors: Department of Gastroenterology, Division of Pediatrics, University Medical Center Ljubljana, Ljubljana, Slovenia. orel.orel@siol.net
authors: Rok
authors: R
authors: Orel
authors: Gaj
authors: G
authors: Vidmar
mesh_terms: D000293:Adolescent; D001663:Bilirubin / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D004386:Duodenum; D004941:Esophagitis / Q000209:etiology / Q000503:physiopathology*; D004947:Esophagus / Q000737:chemistry; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007419:Intestinal Secretions; D008297:Male; D013997:Time Factors
chemical_list: D001663:Bilirubin