Polyp. Endoscope view of a benign (non-cancerous) stalked polyp in a patient's colon (large intestine). This is an adenoma, a tumour arising from the epithelial tissue lining an organ. If the polyp causes discomfort, for instance by obstructing the flow of food along the intestine, it is removed surgically. Some types of polyp may turn cancerous, and are removed as soon as they are discovered.