The most common presenting symptom of ZES, seen in >90% of patients, is a peptic ulcer, most commonly in the duodenal bulb. Diarrhea is the second most common manifestation, seen in up to 50% of patients, and is multifactorial due to small bowel volume overload, pancreatic enzyme inactivation, and epithelial damage from gastric acid. Patients may have associated malabsorption of nutrients and maldigestion. Finally, patients may present with esophageal lesions ranging from mild esophagitis to ulcerations to Barrett esophagus. The most common locations of gastrinomas are the pancreas and duodenum, often with metastatic disease present at diagnosis.
E16.4 – Increased secretion of gastrin
53132006 – Zollinger-Ellison syndrome