Review article: acidity and volume of the refluxate in the genesis of gastro-oesophageal reflux disease symptoms

Authors


Dr D. Sifrim, Faculty of Medicine K.U. Leuven, Lab G-I Physiopathology, O&N Gasthuisberg, 7th floor, Herestraat 49, 3000 Leuven, Belgium.
E-mail: daniel.sifrim@med.kuleuven.ac.be

Summary

Background A number of mechanisms, other than acid reflux, may be responsible for the symptoms of gastro-oesophageal reflux disease.

Aim 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.

Conclusion 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.

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