title: Mechanisms of gastro-oesophageal reflux in preterm and term infants with reflux disease.
abstract: BACKGROUND
  Transient lower oesophageal sphincter relaxation (TLOSR) is the predominant mechanism of gastro-oesophageal reflux (GOR) in healthy infants but the mechanisms of GOR in infants with GOR disease (GORD) are poorly understood.
  
  
  OBJECTIVE
  To measure the occurrence of TLOSR, GOR, and gastric emptying (GE) rate in preterm and term infants with GORD.
  
  
  METHODS
  Thirty six infants were studied and grouped as normals or GORD based on a routine clinical assessment and confirmation of an assessment of GORD by reflux symptom charts and oesophageal pH monitoring.
  
  
  METHODS
  A micromanometric assembly incorporating a micro pH electrode recorded oesophageal motility and pH. GE rate was determined using the (13)C-octanoic acid breath test.
  
  
  RESULTS
  TLOSR was the predominant mechanism of GOR, triggering 50-100% of GOR episodes (median 91.5%). Abdominothoracic straining significantly increased the occurrence of GOR in association with TLOSR. In infants with GORD, the number of TLOSRs overall was similar to normals but the proportion of TLOSRs accompanied by acid GOR was significantly higher than in normals (16.5% v 5.7%, respectively; p<0.001). Infants with GORD had a similar GE rate to normals.
  
  
  CONCLUSIONS
  In infant GORD, acid reflux associated TLOSRs are abnormally common and likely to be a major contributing factor to the pathophysiology of GORD. Infants with GORD do not have delayed GE.
authors.affiliation: Centre for Paediatric and Adolescent Gastroenterology, Women's and Children's Hospital and Department of Paediatrics, University of Adelaide, North Adelaide, Australia. taher.omari@adelaide.edu.au
authors.forename: T I
authors.initials: TI
authors.lastname: Omari
authors.forename: C P
authors.initials: CP
authors.lastname: Barnett
authors.forename: M A
authors.initials: MA
authors.lastname: Benninga
authors.forename: R
authors.initials: R
authors.lastname: Lontis
authors.forename: L
authors.initials: L
authors.lastname: Goodchild
authors.forename: R R
authors.initials: RR
authors.lastname: Haslam
authors.forename: J
authors.initials: J
authors.lastname: Dent
authors.forename: G P
authors.initials: GP
authors.lastname: Davidson
mesh_terms: D000704:Analysis of Variance; D001942:Breast Feeding; D004943:Esophagogastric Junction / Q000503:physiopathology*; D005260:Female; D005746:Gastric Emptying / Q000502:physiology; D005764:Gastroesophageal Reflux / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007225:Infant Food; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008365:Manometry