Having a colonoscopy

A colonoscopy involves a specially trained health professional putting a thin tube into your anus (bottom). There is a very small camera on the end of the tube which is used to examine the lining of your bowel to see if there are any problems. A colonoscopy can identify whether polyps or cancers are present.

If a cancer is found, a small sample or biopsy will be taken. If polyps (growths) are found, they will generally be removed. The samples or removed polyps are sent to the laboratory to check for cancer.

Polyps are not cancers, but may turn into a cancer over a number of years. Removing polyps is usually painless.

About 7 in 10 people who have a colonoscopy as part of the National Bowel Screening Programme will have polyps. If the polyps are removed, this may prevent cancer developing.

About 7 in 100 people who have a colonoscopy as part of the National Bowel Screening Programme will be found to have cancer and most will require treatment.

The preparation for colonoscopy varies slightly from district health board to district health board. You’ll be sent information by your district health board with your colonoscopy appointment letter.

Are there risks from a colonoscopy?

Colonoscopy is considered a safe procedure. However, as with most medical procedures, problems can sometimes happen.

There is a small risk the colonoscopy procedure itself, or removal of polyps, will cause serious bleeding or damage to your bowel and you may need further treatment.

Colonoscopy and follow-up tests and treatment are free

If you are eligible to take part in the National Bowel Screening Programme, the colonoscopy and any follow-up tests or treatments within the public health system are free.