Pathophysiology and diagnosis of gastroesophageal reflux disease.

The pathophysiology and diagnosis of gastroesophageal reflux disease (GERD) are discussed. GERD is a clinical syndrome involving the reflux of gastric contents into the esophagus. It is distinguished from the reflux that occurs normally in the general population. A low pressure exerted by the lower esophageal sphincter (LES) and inappropriate spontaneous relaxation of the LES may contribute to the development of GERD. Other possible contributory factors are increased intra-abdominal pressure and impaired esophageal clearance. The amount and concentration of refluxed gastric acid, proteolytic enzymes, and bile acids are among the determinants of the extent of esophageal injury. Heartburn is a specific symptom of GERD. Other symptoms include coughing, wheezing, hoarseness, epigastric pain, and regurgitation. Upper-GI roentgenography, endoscopy, biopsy, 24-hour ambulatory pH monitoring, and esophageal manometry have been used to diagnose and evaluate the disease. The complications of GERD are strictures, hemorrhaging, perforation, aspiration, and Barrett esophagus. The causes of GERD are incompletely understood, but low LES pressure seems important. GERD may lead to serious complications. A broad array of diagnostic approaches is available.