The risks of colonoscopy are rare but you need to know about them so you can make your decision about having the test.
The risks must be compared to the benefit of having the test.
The main risks of a colonoscopy are:
- Perforation – for 1 in every 1,000 tests there is a tear of the lining of the bowel. An operation is nearly always required to repair the hole. The risk of perforation is higher when polyps (small growths) have been removed.
- Bleeding - this may occur where the sample of your bowel was taken or where a polyp has been removed. The risk is about one for every 100-200 tests where this is done. Bleeding is not usually serious and often stops on its own.