gastroesophageal reflux, a backflow of contents of the stomach into the esophagus that is often the result of incompetence of the lower esophageal sphincter. Gastric juices are acidic and therefore produce burning pain in the esophagus. Repeated episodes of reflux may cause esophagitis, peptic esophageal stricture, or esophageal ulcer. In uncomplicated cases treatment consists of elevation of the head of the bed, avoidance of acid-stimulating foods, and regular administration of antacids. In complicated cases surgical repair may provide relief. Also called GERD. See also chalasia, esophagitis, heartburn, hiatal hernia, reflux esophagitis.