Pathophysiology of gastro-oesophageal reflux disease.

Gastro-oesophageal reflux disease (GERD), defined as symptoms or mucosal damage caused by reflux of gastric contents into the esophageal body, is a multifactorial disorder. Malfunctioning of the anti-reflux barrier at the esophagogastric junction, consisting of the right diaphragmatic crus and the lower esophageal sphincter (LES), is the pivotal abnormality. Other factors such as impaired esophageal clearance, decreased resistance of the esophageal mucosa and delayed gastric emptying, may contribute.