Surveillance tests

Information for the public

Some tests may not be suitable for you, depending on your exact circumstances. If you have questions about specific tests and options, please talk to a member of your healthcare team.

There are different types of surveillance test and these are described in the box below. The test usually offered is colonoscopy.

Your specialist should give you information about what to expect during and after the test and whether you will need a sedative. They will also discuss with you any risks of the test and how to prepare for it, for example, what you can eat before the test and when, or whether you need to take a laxative to empty your bowel.

Each time you have a surveillance test, the results will help your specialist decide (in discussion with you) when you should come for your next surveillance test, or if you need to have another surveillance test.

Surveillance tests

The NICE guideline recommends the following tests to look for changes in the large bowel, including signs of colorectal cancer.

Colonoscopy: a thin flexible tube containing a tiny video camera is inserted through the rectum (also called the back passage) into the large bowel. This shows any abnormal areas or polyps inside the large bowel. Tissue samples, known as biopsies, can be taken during the procedure. You should be offered this test if you have had polyps removed. Sometimes a colonoscopy may need to be repeated if it has not examined all of the large bowel.
Chromoscopy: a dye is used during colonoscopy to show up any abnormal areas. You should be offered chromoscopy if you have inflammatory bowel disease.
Computed tomographic (CT) colonography: a CT scan of the large bowel that produces two- and three-dimensional images. You may be offered this test if you have had polyps removed and a colonoscopy is not suitable for you.
Barium enema: an X-ray is taken after the large bowel is filled with barium fluid inserted through a tube into the rectum. Barium shows up any abnormal areas when the X-ray is taken. You may be offered this test if you have had polyps removed and a colonoscopy is not suitable for you.