title: Review article: acidity and volume of the refluxate in the genesis of gastro-oesophageal reflux disease symptoms.
abstract: BACKGROUND
  A number of mechanisms, other than acid reflux, may be responsible for the symptoms of gastro-oesophageal reflux disease.
  
  
  OBJECTIVE
  To assess the importance of non-acid reflux mechanisms.
  
  
  METHODS
  This review is based on presentations and discussion at a workshop, where specialists in the field analysed data relating to these mechanisms.
  
  
  RESULTS
  Weakly acidic reflux, pH (4-7), detected with impedance-pHmetry is associated with regurgitation and atypical gastro-oesophageal reflux disease symptoms. It is not clear whether pepsin and trypsin can elicit symptoms, but bile can elicit heartburn. The magnitude of reflux-induced oesophageal distension can be determined by high frequency ultrasonography and is not reduced by proton pump inhibition, suggesting that persisting symptoms 'on' a proton pump inhibitor may still be due to oesophageal distension by non-acidic reflux. Exaggerated longitudinal muscle contraction can induce non-acid-related heartburn. Preliminary studies showed a positive effect of baclofen, surgery or endoscopic procedures to reduce weakly acidic reflux.
  
  
  CONCLUSIONS
  Mechanisms other than acid reflux are involved in some of the symptoms of gastro-oesophageal reflux disease. Controlled outcome studies are needed to clarify their roles and the indications for antireflux procedures in patients with persistent symptoms whilst 'on' a proton pump inhibitor.
authors: Center for Gastroenterological Research, Catholic University of Leuven, Leuven, Belgium. daniel.sifrim@med.kuleuven.ac.be
authors: D
authors: D
authors: Sifrim
authors: R
authors: R
authors: Mittal
authors: R
authors: R
authors: Fass
authors: A
authors: A
authors: Smout
authors: D
authors: D
authors: Castell
authors: J
authors: J
authors: Tack
authors: H
authors: H
authors: Gregersen
mesh_terms: D000553:Ambulatory Care / Q000379:methods; D003371:Cough / Q000209:etiology; D005744:Gastric Acid / Q000502:physiology*; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000188:drug therapy / Q000209:etiology* / Q000601:surgery; D006801:Humans; D006863:Hydrogen-Ion Concentration; D054328:Proton Pump Inhibitors
chemical_list: D054328:Proton Pump Inhibitors