Carcinoid tumor is a type of neuroendocrine tumor that can be found throughout the gastrointestinal tract as well as other organs such as the lung, liver, and ovary. Less than 15% of GI carcinoid tumors originate from the colon.

In general, they are slow-growing tumors and symptoms can be variable, dependent on the location. Carcinoid syndrome may be seen in 8% of patients with a carcinoid tumor and diarrhea is the most common presentation.