Surgical removal of all or part of the stomach to treat peptic ulcers. It eliminates the cells that secrete acid and halts the production of gastrin, the hormone that stimulates them. Once a common operation, it is now a last resort. The usual procedure, antrectomy, removes the lower half of the stomach (antrum), the chief site of gastrin secretion. The remaining stomach is joined to the duodenum. Subtotal gastrectomy removes up to three-quarters of the stomach. The greatest drawback is malnutrition caused by decreased appetite and inability to digest food.