<prompt> Answer this question truthfullyCan you provide an overview of Zollinger-Ellison syndrome?  <response>: <reason> Symptoms of Zollinger-Ellison syndrome include diarrhea, odynophagia, nausea, and hematemesis.Common physical examination findings of Zollinger-Ellison syndrome include epigastric tenderness, pallor, and jaundice.An elevated concentration of fasting serum gastrin level and secretin stimulation test may be helpful in the diagnosis of Zollinger-Ellison syndrome.Abdominal CT scan may be helpful in the diagnosis of Zollinger-Ellison syndrome caused by gastrinoma. Gastrinomas are frequently multiple and often extrapancreatic 90 located in the gastrinoma triangle. Thus, they can be difficult to locate. For this reason, multiphase contrast enhanced thin slice cross-sectional imaging is ideal. Findings on Abdominal CT scan suggestive of gastrinoma include clearly defined, well-enhanced mass.Abdominal MRI may be helpful in the diagnosis of Zollinger-Ellison syndrome caused by gastrinoma. Findings on abdominal MRI suggestive of Zollinger-Ellison syndrome include solitary lesion or multiple lesions.Abdominal ultrasound may be helpful in the diagnosis of Zollinger-Ellison syndrome caused by gastrinoma.Endoscopic ultrasound and somatostatin receptor scintigraphy SRS octreotide scan may be helpful in the diagnosis of Zollinger-Ellison syndrome caused by gastrinoma.Other diagnostic studies for Zollinger-Ellison syndrome include upper endoscopy, which demonstrates erosive esophagitis, thickened gastric folds, and antral erosions. 