Colonoscopy is a procedure to look inside your large bowel. It’s used as a cancer screening test and to investigate symptoms affecting your bowel. It’s sometimes called a lower gastrointestinal endoscopy or an lower GI endoscopy. A sigmoidoscopy is a lower GI endoscopy that only looks at part of the large bowel.
About colonoscopy
Colonoscopy is a type of endoscopy. In a colonoscopy, a long, flexible tube called a colonoscope is passed into your back passage (rectum) to look inside your large bowel. The colonoscope has a light and camera or video camera on the end of it. This allows the colonoscopist (the professional performing the procedure) to see into your bowel and take images.
Why do I need a colonoscopy?
There are several reasons why you might have a colonoscopy. These include:
- As a screening test to check for early signs of bowel or colon cancer (colorectal cancer) and polyps (growths that could turn into cancer).
- To investigate bowel symptoms such as abdominal pain, diarrhoea or constipation, and blood in your poo or other abnormalitites in bowel habits. It can help to confirm a diagnosis of bowel conditions including cancer, ulcers or inflammatory bowel disease, like Crohn’s disease or ulcerative colitis.
- To monitor your bowel if you have a bowel condition or previously had treatment for a bowel condition.
- To follow up on previous tests with further investigation or treatment.
In the UK, bowel screening is offered to everyone between the ages of 50 and 74 by the NHS. As part of the NHS screening programme, you’re sent a home test kit called a faecal immunochemical test (FIT) every two years. You’re invited for a colonoscopy if you have an abnormal result on this test.
Private care for colonoscopy
Colonoscopy is available on the NHS and privately, both for screening tests and for investigation of bowel symptoms. If you have health insurance, check whether it covers colonoscopy.
For a private screening test, you’ll usually need a consultation with a doctor first, to discuss your health, medical history and check whether the test is suitable for you. If you’re having private colonoscopy to check bowel symptoms, you should inform your GP of your symptoms but can self refer to a private consultant.
A colonoscopy procedure is similar, whether you have it on the NHS or privately. But there will usually be differences in how you receive your care. You’ll probably have a greater choice of when and where you can have the procedure. Depending on why you’re having a colonoscopy, you’re likely to be able to have the procedure done faster through private care.
Preparing for a colonoscopy
Your bowel needs to be empty to have a colonoscopy, so that your doctor can clearly view your bowel lining. To do this, you may be asked to follow a low fibre diet for a couple of days before your procedure and to take laxatives the day before. Sometimes you may be asked to stick to clear liquids the day before your test. It’s important to follow any instructions you’re given – your procedure may not be able to go ahead if you don’t.
Tell your doctor about any medications you normally take. They may ask you to stop taking them before your procedure, or to reduce your dosage.
What happens in a colonoscopy?
You will usually have a colonoscopy as an outpatient in an endoscopy unit. This means you have the procedure and go home on the same day.
You’ll be given the choice whether to have your colonoscopy under sedation. Sedation helps you to relax and makes you feel drowsy. You’ll also be offered painkillers.
When you’re ready to begin, you’ll be asked to lie down on your left side and draw your knees up towards your chest. Your endoscopist will gently pass the colonoscope into your back passage, and up into your large bowel. It might feel a bit uncomfortable, but it shouldn’t feel painful.
The clinician will gently pump gas into your bowel so that they can see inside more clearly. They will be able to take images from inside your bowel during the procedure, which they can see on a screen. They may take a biopsy (tissue sample) and perform any treatment that’s needed, such as removing polyps, during the procedure.
At the end of the procedure, the colonoscopist will slowly remove the colonoscope.
Recovery and what to expect after a colonoscopy
If you’ve had sedation, you’ll need to wait at the hospital for a couple of hours while you recover. When you’re ready to go home, a friend or relative will need to drive you and stay with you overnight. Try to keep the rest of the day free so you can rest and recover at home.
You may have bloating and cramping discomfort after a colonoscopy. This is due to the gas that’s passed into your bowel. You’ll usually feel better within a few hours.
Your doctor may be able to discuss some of the findings from the colonoscopy with you straight away. But it may take up to a couple of weeks to get results such as biopsies. You should be told when to expect the results of any tests before you leave the hospital.
Potential complications of colonoscopy
Colonoscopy is generally considered a very safe procedure. But as with any medical procedure, it does come with a risk of complications. These may include:
- The doctor is unable to see all of your bowel during the procedure
- Bleeding following a biopsy or polyp removal
- Perforation (tearing) of your bowel wall. This is not common.
- Reaction to sedative medicines, such as breathing problems, however serious problems are rare as you are monitored during the colonscopy.
Serious complications after colonoscopy are rare. If you have symptoms such as severe pain after your procedure, contact the hospital straight away.
Colonoscopy costs and fees
If you have private medical insurance, check with your insurer whether they will cover the cost of colonoscopy. This may depend on the reason why you’re having it.
You can also pay for colonoscopy yourself (known as self-funding). Typically, an initial consultation for a diagnostic colonoscopy will cost between £180 and £250. The procedure itself costs between £300 and £600. Colonoscopy costs in the UK vary depending on where you live. If you go ahead with the procedure, you’ll be offered one of the following.
- An all-inclusive ‘package price’, where you know the full costs before having the procedure. Not all consultants and hospitals offer this.
- A ‘fee-per-service’ deal, where you receive different invoices from the consultant, the anaesthetist and the hospital. You often won’t know the full costs until you receive the invoices.
For more information, you can read our guide on self-pay.
References
- Colonoscopy. Cancer Research UK. https://www.cancerresearchuk.org/about-cancer/tests-and-scans/colonoscopy, last reviewed 4 August 2022.
- Colonoscopy. Encyclopaedia Britannica. https://www.britannica.com/science/colonoscopy, last updated 6 August 2023.
- Stauffer CM, Pfeifer C. Colonoscopy. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK559274/, last updated 24 July 2023.
- Endoscopy. Encyclopaedia Britannica. https://www.britannica.com/science/endoscopy, last updated 8 September 2023.
- Endoscopy. Healthline. https://www.healthline.com/health/endoscopy, last reviewed 12 March 2018.
- Adult screening programme: Bowel Cancer. https://view-health-screening-recommendations.service.gov.uk/bowel-cancer/. Last reviewed
- Bowel cancer screening: having a colonoscopy. NHS England. https://www.gov.uk/government/publications/bowel-cancer-screening-colonoscopy/bowel-cancer-screening-having-a-colonoscopy-fit, updated 28 July 2022.
- Caring for someone recovering from a general anaesthetic or sedation. Royal College of Anaesthetists, November 2021. https://www.rcoa.ac.uk/sites/default/files/documents/2021-11/12-SedationCarer2021web.pdf.
