A colon polyp is a growth on the lining of the colon or rectum. The two most common types of polyps found in the colon are adenomatous and hyperplastic. Adenomatous polyps have the potential to become cancer. Hyperplastic polyps are typically innocent and not pre-cancerous.
Most polyps are small and do not cause any symptoms. Large polyps can cause rectal bleeding or chronic blood loss with resultant anemia. Rarely, large polyps can cause obstruction of the colon.
Colon polyps are most commonly detected during a colonoscopy. They may also be found with other forms of diagnostic testing, such as a barium enema or virtual colonoscopy.
All polyps should be removed during a colonoscopy. Small polyps can be removed by pinching away the abnormal tissue with an instrument called a biopsy forceps. Larger polyps can be removed using a snare, which is a wire loop. The polyp is grasped with the snare and electrocautery is used to cut through the tissue and cauterize any blood vessels to prevent bleeding. Extremely large polyps may not be amenable to removal using these techniques and may require surgical resection.