Patients with Zollinger-Ellison Syndrome suffer from ulcers of the upper gastrointestinal tract, higher than normal levels of gastric acid, and tumors of the pancreas known as non-beta islet cell tumors. Patients with Zollinger-Ellison Syndrome require continuous control of their gastric acid secretion. If gastric acid levels are permitted to rise higher than normal, patients may develop severe ulcers and other complications.