A cause to consider for chronic unresolving diarrhea

A 36-year-old male who carried a diagnosis of irritable bowel syndrome presented with chronic watery diarrhea and was found to have hepatomegaly on physical exam. A computed tomography (CT) scan of the abdomen revealed hepatomegaly with lesions suspicious for metastatic disease. A colonoscopy revealed a polypoid lesion in the terminal ileum, which was biopsied, revealing a neuroendocrine tumor (NET). He was treated with palliative octreotide and chemoembolization of liver metastases until disease progression. The case highlights the importance of considering functional NETs, especially carcinoid syndrome, in patients with chronic unresolving diarrhea, since early diagnosis allows for further treatment options that can prolong survival.