If your bowel screening test result is positive, it means you will need a further investigation. This will usually be a colonoscopy. The colonoscopy is free if you are eligible.

Having a colonoscopy

During a colonoscopy, a specially trained doctor or nurse looks directly at the lining of your large bowel (colon), using a very small camera. The camera is on the end of a thin flexible tube, which is put into your bowel through your anus (bottom).

The camera is used to look at the lining of your bowel to see if there are any problems.

A colonoscopy can find out whether there are polyps or cancers in the bowel. Polyps are small growths that are not cancers but may develop into a cancer over a number of years. If found, polyps will generally be removed to help prevent cancer. The removed polyps are sent to a laboratory to check for any cancer cells. 

Some people find a colonoscopy a little uncomfortable. Before the colonoscopy you will be given medication that makes you sleepy and helps make the colonoscopy more comfortable.

Someone from your local bowel screening programme will contact you and organise a date for your colonoscopy.

About 7 in 10 people who have a colonoscopy as part of the National Bowel Screening Programme will have polyps.

About 7 in 100 people who have a colonoscopy as part of the programme will be found to have cancer.

At least a third of the cancers detected are at an early stage when they can often be successfully treated.

Colonoscopy risks

Colonoscopy is usually 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 bleeding or damage to your bowel. If this happens, you may need further treatment.

Preparing for a colonoscopy

Before you have your colonoscopy, your bowel needs to be emptied so your bowel lining can be clearly seen.

Instructions on how to do this will come with your appointment letter.