Heidenhain pouch (HP) dogs were studied. After gastroduodenostomy (GD) gastric emptying time was unaffected, but cineradiography showed that the strength of the antral contractions diminished considerably, while the number of peristaltic waves increased. ‘Circus movements’ of the barium meal through the GD to the duodenum and back to the stomach through the pylorus occurred. No significant changes in food-stimulated HP acid secretion or serum gastrin response were observed. After parietal cell vagotomy (PCV) gastric emptying and motility was unaffected, but food-stimulated HP acid secretion and serum gastrin response increased significantly. After addition of a GD to PCV gastric emptying time decreased significantly but similar changes in antral motility occurred as after GD alone. The food-stimulated HP acid secretion and serum gastrin response became significantly reduced. Fasting HP acid secretion and serum gastrin concentration were not significantly altered by any of the surgical procedu