We welcomed the systematic review by Havemann et al (Gut 2007;56:1654) further highlighting the significance of the association between gastro-oesophageal reflux disease (GORD) and asthma. The importance of this association is underlined by the magnitude of published studies concerning this subject (731 studies evaluated in Havemann’s review). The reviewers conceded that the direction of causality and the underlying mechanism responsible for this association remain undetermined. Mechanisms postulated include hyperexpansion of the asthmatic chest leading to failure of the gastro-oesophageal junction (GOJ) with attendant reflux symptoms, or shared stimulation of vagus nerve-mediated reflex arcs resulting in both bronchial smooth muscle constriction (causing asthma) …