Zollinger-Ellison syndrome is a rare condition in which one or more tumors grow in the pancreas or in the upper part of the small intestine. The tumors are called gastrinomas. These gastrinomas produce large amounts of the hormone gastrin. Gastrin causes the stomach to produce too much acid, which leads to peptic ulcers. High gastrin levels also can cause diarrhea, belly pain and other symptoms.
Zollinger-Ellison syndrome may occur at any time in life. However, people usually find out they have it sometime between ages 20 and 60. Medicines to cut down stomach acid and heal the ulcers are the usual treatment. Some people also may need surgery to remove tumors.