Zollinger-Ellison syndrome is a complex condition in which one or more tumors form in your pancreas or the upper part of your small intestine (duodenum). These tumors, called gastrinomas, secrete large amounts of the hormone gastrin, which causes your stomach to produce too much acid. The excess acid, in turn, leads to peptic ulcers.
Zollinger-Ellison syndrome (ZES) is rare. The disease may occur at any time in life, but people are usually diagnosed between ages 30 and 50. Medications to reduce stomach acid and heal the ulcers is the usual treatment for Zollinger-Ellison syndrome.