Gastro-oesophageal reflux disease. Conceptual computer artwork of gastro-oesophageal reflux disease (GORD), represented by boiling test tubes. GORD, also known as acid reflux, is an advanced form of heartburn. It occurs when the sphincter separating the stomach and the oesophagus does not close properly and stomach acid leaks back into the oesophagus. This is depicted here as green liquid splashing up the sides of boiling test tubes. Frequent reflux of acid up the oesophagus can lead to damage (GORD) and oesophagitis, inflammation of the lining of the oesophagus. The condition is made worse by obesity, smoking and excessive alcohol consumption.