--- title: "Colonoscopy: What to Expect | HealthAnswers" description: "A colonoscopy is a test that uses a flexible camera to examine the whole colon, used after a positive FIT, for symptoms or surveillance, and to remove…" url: https://healthanswers.co.uk/tests/colonoscopy/ robots: noindex --- # Colonoscopy: What to Expect | HealthAnswers Tests & investigations A colonoscopy is a test that uses a flexible camera to examine the whole colon, used after a positive FIT, for symptoms or surveillance, and to remove polyps. Written by HealthAnswers editorial team Medically reviewed by [HealthAnswers UK doctor review panel](https://healthanswers.co.uk/our-doctors/) Reviewed 3 July 2026 ## Quick answer What is a colonoscopy? A colonoscopy is a test that inspects the whole colon using a flexible camera, usually carried out under sedation. It requires bowel preparation with laxatives the day before. The test can remove polyps to help prevent cancer, and it is used after a positive FIT, for symptoms or for surveillance. General UK health information, not a diagnosis. In an emergency call 999 ; for urgent advice use [NHS 111](https://111.nhs.uk/) (GP out-of-hours in Northern Ireland). On this page 4 sections ## Key facts about the colonoscopy - Bowel preparation is essential to give clear views of the colon. - Sedation is common, so you will need someone to escort you home. - Polyps can be removed during the procedure, known as polypectomy. - There is a small, rare risk of perforating the bowel. - CT colonography is an alternative if a colonoscopy is unsuitable. ## What a colonoscopy is used for A colonoscopy is used to investigate bowel symptoms, to follow up a positive FIT screening result, and to monitor conditions such as inflammatory bowel disease and polyps. It is regarded as the gold standard for viewing the inside of the colon. ## How to prepare for a colonoscopy In the days before the test, you will usually be asked to follow a low-residue diet. You then take a laxative solution to empty the bowel, so it helps to stay near a toilet while it works. ## What happens during a colonoscopy On the day, you are usually given sedation, along with oxygen and monitoring throughout the procedure. The camera is passed through the colon, ideally as far as the caecum, and photographs are taken to document the examination. ## Recovering after a colonoscopy Plan to rest for the remainder of the day and arrange for someone to escort you home, as the sedation can affect you afterwards. Report any complications promptly, especially severe pain, [fever](https://healthanswers.co.uk/symptoms/high-temperature/) or bleeding. ## ! When to speak to a doctor about the colonoscopy A GP will refer you for a colonoscopy if you have symptoms or after a positive screening result. Call **999** or go to A&E if you have severe pain or bleeding after the procedure. ## Common questions about the colonoscopy Is the bowel preparation for a colonoscopy unpleasant? The preparation uses strong laxatives to empty the bowel, which many people find the most unpleasant part of the test. It is important to follow the instructions precisely, as a clear bowel is needed for a successful examination. Does a colonoscopy hurt? Sedation is usually given, so most people remember little of the procedure and feel little discomfort. Some people notice bloating or gas discomfort afterwards, which soon settles. What happens if a polyp is removed during a colonoscopy? Any polyp that is removed is sent to the laboratory for analysis under a microscope. How often you need follow-up colonoscopies depends on the type and number of polyps found. What are the risks of a colonoscopy? Complications such as bleeding or perforation of the bowel are rare. Seek medical help if you have severe pain, a fever, or bleeding after the procedure. ## Sources - [NHS — Colonoscopy](https://www.nhs.uk/conditions/colonoscopy) - [NHS — Bowel Cancer Screening](https://www.nhs.uk/conditions/bowel-cancer-screening) ## How we reviewed this page Medically reviewed by the [HealthAnswers UK doctor review panel](https://healthanswers.co.uk/our-doctors/) First published 28 June 2026 Medically reviewed 3 July 2026 Next review due 3 July 2029 or sooner if NHS or NICE guidance changes Written by HealthAnswers editorial team. Published by HealthAnswers (Elite Digital AI Solutions Ltd). [How we review content](https://healthanswers.co.uk/about/how-we-review/) · [Report a problem with this page](mailto:corrections@healthanswers.co.uk?subject=Problem%20with%3A%20Colonoscopy&body=Page%3A%20https%3A%2F%2Fhealthanswers.co.uk%2Ftests%2Fcolonoscopy%2F%0A%0AWhat%20looks%20wrong%20or%20out%20of%20date%3A%0A)