• The rational treatment of gastric ulcer (GU) requires both an understanding of the various causative factors responsible for what is best considered a spectrum of disorders, as well as a familiarity with the newer antisecretory and cytoprotective therapies that are available. Gastric ulcers that fulfill the criteria to be peptic ulcers (ie, occur in the antrum in the presence of excess luminal acid, with or without a coexisting duodenal ulcer) are best treated with a histamine H2-receptor antagonist. For GUs that develop in the setting of normal or reduced acid output, or those that occur as a result of direct (ie, drug-induced or bile acid-related) mucosal injury, use of a cytoprotective agent (eg, sucralfate) is the treatment of choice. Any GU that falls to heal within 12 to 15 weeks should be carefully examined to exclude the presence of a malignant neoplasm and should be considered for surgical resection. (Arch Intern Med 1983;143:264-274)