We prospectively studied 15 consecutive patients treated for alkaline reflux gastritis to determine the gastric motility pattern associated with this disease and the effects of Roux-Y gastrojejunostomy on gastric emptying. Eleven patients had previous antrectomies (the Billroth I procedure in 4 and the Billroth II procedure in 7), and 4 had previous cholecystectomies. Gastric emptying was measured before and after Roux-Y reconstruction by computer analysis of data from a scintillation camera using technetium 99m tagged chicken liver mixed with beef stew. Gastric emptying was also measured in another 10 patients who had previous Roux-Y gastrojejunostomies and were thought from clinical findings to have gastroparesis. In the patients with alkaline gastritis, before surgery gastric emptying was normal in 25 percent, rapid in 45 percent, and delayed in 30 percent. After Roux-Y reconstruction, the rate of gastric emptying increased in 25 percent of patients, decreased in 45 percent, and did not change in 30 percent. Gastric bezoars developed in half of the patients whose gastric emptying decreased after surgery. There were no technical features of the operations nor mechanical abnormalities of the reconstructions that characterized the patients whose gastric emptying slowed postoperatively. Forty percent of the patients studied only after Roux-Y reconstruction had rapid gastric emptying, 30 percent had normal gastric emptying, and 30 percent had delayed gastric emptying. These data show that patients with alkaline reflux gastritis do not have a single pattern of gastric emptying, and Roux-Y reconstruction has no consistent effect on gastric emptying.