Pathophysiology and treatment of gastro-oesophageal reflux disease

Gastro-oesophageal reflux occurs when the pressure barrier of the lower oesophageal sphincter (LOS) fails due to a low basal pressure (less than or equal to 6 mm Hg), sphincteric relaxations or a noncompensated increase in intragastric pressure. This reflux becomes pathological when it leads to symptoms severe enough for the patient to seek medical help or results in reflux oesophagitis or its complications. Damage to the oesophageal mucosa develops when the balance between aggressive and defensive factors is no longer in equilibrium. The main aggressive factor is acid-pepsin or alkaline bile secretion. Defence against this aggression is based on rapid removal of the refluxate from the oesophagus (oesophageal clearance) and on poorly understood mucosal resistance. The length of time acid is in contact with the oesophageal mucosa is shortened by adoption of an upright position, by swallow-induced oesophageal peristalsis and saliva. Treatment of pathological reflux aims (1) to decrease acid aggression by means of H2-receptor antagonists or proton pump inhibitors; (2) to strengthen the anti-reflux barrier and improve oesophageal clearance by prokinetic drugs that increase the LOS pressure and enhance peristaltic contractions; and (3) to boost mucosal resistance by sucralfate or prostaglandin analogues. Initial treatment of gastro-oesophageal reflux disease may be symptomatic provided that there are no alarming symptoms, such as dysphagia, anaemia or weight loss. Usually either H2-receptor blockers or prokinetic drugs are used. Endoscopy is indicated whenever alarming symptoms are present and when there is insufficient symptomatic improvement after a 4-6-week therapeutic trial. Moderate oesophagitis may be treated in the same way.(ABSTRACT TRUNCATED AT 250 WORDS)