A Case of Functional Bowel Disease Misdiagnosed as Carcinoid Syndrome

An elevated urinary 5-hydroxyindoleacetic acid (U5-HIAA) is typically thought of to be related to carcinoid syndrome. It is widely known that several other etiologies can cause high levels; however, those etiologies typically cause mild elevations. We present a unique situation of a highly elevated U5-HIAA not because of a neuroendocrine tumor. Gastroenterologists need to have an approach in mind if they encounter this predicament. We aim to raise awareness of this situation to emphasize the importance of a thorough medication history and avoid unnecessary testing.