Esophageal exposure to acid is a major determinant in the pathogenesis of reflux esophagitis. In this study, we analyzed the esophageal peristaltic function of 177 patients and asymptomatic volunteers for abnormalities that could lead to prolonged esophageal acid clearance. The subjects were divided into five groups: normal volunteers, patient controls, patients with noninflammatory gastroesophageal reflux disease, patients with mild esophagitis, and ones with severe esophagitis. Manometric data were analyzed for the occurrence of failed primary peristalsis, for the occurrence of feeble peristalsis in the distal esophagus, and for hypotensive lower esophageal sphincter pressure. From an analysis of the data on control patients, peristaltic dysfunction was defined as the occurrence of either failed primary peristalsis or hypotensive peristalsis in the distal esophagus for over half of the test swallows. Peristaltic dysfunction was increasingly prevalent with increasing severity of peptic esophagitis, occurring in 25% of patients with mild esophagitis and 48% of patients with severe esophagitis. A correlation did not exist between the occurrence of peristaltic dysfunction and hypotensive lower esophageal sphincter pressure (less than or equal to 10 mmHg). We conclude that peristaltic dysfunction occurs in a substantial minority of patients with peptic esophagitis and could contribute to increased esophageal exposure to refluxed acid material.