Endoscopic examination of 50 patients with gastroesophageal reflux showed 26 with and 24 without esophagitis. Distal esophageal sphincter (DES) characteristics of the two groups were similar. All patients had abnormal acid gastroesophageal reflux (GER) on 24-hour pH monitoring of the distal esophagus compared to normal subjects. Patients with esophagitis did not have significantly greater acid exposure than those without esophagitis. Abnormal alkaline GER occurred in only five patients, two with and three without esophagitis. Esophageal clearance was impaired in patients with esophagitis compared to patients without esophagitis as determined by the acid clearance test and the number of reflux episodes of 5 minutes' duration or longer during 24-hour esophageal pH monitoring. Patients with esophagitis also had more frequent reflux episodes than those without esophagitis. Gastric emptying was significantly delayed in patients with esophagitis compared to those without esophagitis who were similar to normal subjects. When patients were analyzed in terms of position of reflux, combined refluxers had the highest, supine refluxers intermediate, and upright refluxers the lowest incidence of esophagitis. Gastric emptying in combined and supine refluxers was similar to the group of patients with esophagitis. Upright refluxers were distinguished by rapid gastric emptying compared to normal subjects and, as such, are a unique entity. We conclude that the development of esophagitis in a patient with an incompetent cardia is related to impaired esophageal clearance and delayed gastric emptying.