Although many theories have been advanced to explain the etiology of duodenal ulcer, there is ample evidence that this is an acid-engendered disease. Patients with duodenal ulcer secrete excessive quantities of acid, both by day and by night, and the gastric and duodenal pH is significantly lower than that of the nonulcer patient. The surgical treatment of duodenal ulcer is directed toward the control of excessive acid secretion; and if acid secretion is significantly reduced, the treatment is effective.
A decade ago it was thought that the physiology of gastric secretion had at last been settled. The secretion of gastrin by the antrum was finally acknowledged to be an important source of gastric acid stimulation. Acid control was stimulated by impulses along the vagi, by food in the region of the antrum, or by food in the intestine. It could be controlled by dividing the vagi, excising the antrum, or