Abstract
Gastrinoma is a rare neuroendocrine tumor characterized by the hypersecretion of gastrin. Early diagnosis is challenging due to its rarity, and patients present to the outpatient department with nonspecific complaints such as diarrhea, weight loss, and fatigue, which often lead to a broad differential diagnosis. This report presents the case of a 59-year-old female who has come to the internal medicine department for a workup of chronic diarrhea, low-grade fever, 8kg weight loss, and severe reflux of eight months duration, not responding to empiric therapy. After multiple hospital visits and evaluations, she was found to have duodenal gastrinoma. This case report aims to create awareness and underscores the importance of considering neuroendocrine tumors as an initial differential diagnosis for patients with nonspecific or unexplained gastrointestinal symptoms to facilitate early diagnosis.