Review article: the pathophysiology of gastro-oesophageal reflux disease

Background Gastro-oesophageal reflux disease (GERD) is a common condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications. Aim To review the current knowledge on the underlying factors contributing to GERD, with particular emphasis on the most recent research. Methods Literature searches were conducted in Medline and EMBASE. The abstracts from recent large congresses were also reviewed to ensure coverage of the latest findings. Results The pathophysiological factors causing GERD can be split into those inducing greater exposure of the oesophagus to stomach contents, and those that provide increased perception of reflux or increased mucosal damage. Transient lower oesophageal sphincter relaxations, which are likely to be triggered by gastric distension, appear to be a key physiological cause of GERD. Excessive reflux may also be provoked by impaired oesophageal or gastric clearance mechanisms. Pre-epithelial, epithelial and post-epithelial defences all normally protect the oesophagus from injury, and may be compromised in individuals with GERD. Heartburn could also be caused by oesophageal hypersensitivity as a result of visceral neural pathway dysfunction. Conclusion The pathophysiology of GERD is multifactorial, and abnormalities in the gastro-oesophageal junction, the stomach, the oesophagus and the nervous system may all contribute to this disease state.