--- 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. ## Who is this page for? This page is for people in the UK who want a plain-English overview of Colonoscopy, including when to seek help and what NHS care usually involves. It explains general information, not what is wrong with you personally. ## Who should skip this page? Skip this page if you need a diagnosis, a prescription, or emergency care. It cannot replace a GP, pharmacist, NHS 111 or 999. If you are in immediate danger, call 999; for urgent advice that is not life-threatening, call 111 in England, Scotland or Wales, or use your GP out-of-hours service 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 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)