Hypersecretion of gastric acid and hypergastrinaemia occur when the antrum of the stomach is transposed as a diverticulum to the colon. Thus, when an antral pouch is transposed to increase bladder capacity or to replace the bladder as a gastrocystoplasty, similar pathophysiological disturbances can be anticipated. However, previous studies in our laboratories in dogs have shown that acid overproduction and stomal ulcerations do not occur. This paper reports the results of gastrocystoplasty in 13 patients followed up from 1 to 6 years. Gastric acid hypersecretion and hypergastrinaemia did not occur.