We studied 25 consecutive patients with noncirrhotic portal hypertension to determine whether portal hypertensive gastropathy occurred and whether it was related to hypoacidity, hypergastrinemia, or portal venous congestion. Preoperative tests included gastrointestinal endoscopy, gastric mucosal biopsies, gastric acid estimation, and serum gastrin measurements. All patients had a central splenorenal shunt performed during which a full-thickness gastric biopsy was performed. The tests were repeated 3 to 16 months postoperatively. Eight of the 25 patients showed endoscopic evidence of portal hypertensive gastropathy. The shunt procedure reversed the gastropathy in 6 of 7 patients followed up. Mucosal biopsies revealed vascular ectasia in 24 of 25 patients; in 8 of the most severely affected there was partial or complete regression after surgery. The basal and peak acid outputs in the patients were normal for our laboratory at 2.9 +/- 0.25 meq/hour and 16.37 +/- 0.96 meq/hour, respectively. They remained unchanged after surgery. Fasting serum gastrin levels were also normal both before and after surgery. Our findings indicate that venous congestion is the cause of portal hypertensive gastropathy in patients with noncirrhotic portal hypertension and that it can be reversed by a decompressive procedure.