Diagnostic evaluation: gastric acid secretion and pH

The diagnostic value of gastric secretion tests has been found to be lower than what was previously believed. Thus basal and stimulated acid output is normal in most ulcer patients, and this is also so for gastric and duodenal pH. Gastric acid secretion does not separate patients with rapid recurrence after medical treatment from those with a long period of remission, and acid secretion is usually not higher in patients with recurrence after vagotomy than in patients without relapse. Today a gastric acid secretion test is used in patients suspected of the Zollinger-Ellison syndrome and it seems also to be valuable in ulcer patients who do not respond clinically satisfactory to medical treatment.