Zollinger-Ellison syndrome (ZES) is a disease entity which refers to the triad of severe peptic ulcer disease (PUD), gastric acid hypersecretion and non-beta cell gastrin-secreting tumor primarily of the pancreas and duodenum (gastrinoma).
Approximately two-thirds of patients have sporadic ZES while the rest is part of multiple endocrine neoplasia type 1.
ZES should be considered in the differential diagnoses of patients who present with abdominal pain, malabsorption and chronic watery diarrhea.
A high index of clinical awareness is necessary to correctly diagnose ZES.