Stands for GastroEsophageal Reflux Disease, a disorder in which there is recurrent return of stomach contents back up into the oesophagus, frequently causing heartburn, a symptom of irritation of the oesophagus by stomach acid. This can lead to scarring and stricture of the oesophagus, which can require stretching (dilating).10% of patients with GERD develop Barrett's oesophagus which increases the risk of cancer of the oesophagus. 80% of patients with GERD also have a hiatal hernia. (12 Dec 1998)