In 18 patients with hypertrophic pyloric stenosis, endoscopic manometric and studies and pH monitoring were performed. Fourteen patients showed endoscopic evidence of esophagitis. In all 7 patients in whom hematemesis was seen, esophagitis was present. Results of the study strongly suggest that the major site of hemorrhage in this disease is the esophageal mucosa which was possibly damaged by reflux of gastric juice as the result of gastric outlet obstruction.
