Colorectal cancer prevention: colonoscopic surveillance in adults with ulcerative colitis, Crohn's disease or adenomas

Surveillance of the large bowel

Some people with conditions affecting the large bowel (also called the colon) are at higher risk of developing colorectal cancer than other people in the general population and should be offered surveillance. These conditions include:

Surveillance involves regular checks to detect any pre-cancerous changes in the cells of the large bowel (called dysplasia). If dysplasia is found, early treatment can stop it progressing to colorectal cancer. These checks can also pick up early signs of cancer, before the person has any symptoms. This is important because colorectal cancer can be treated successfully if found early enough.

Surveillance of the large bowel is not the same as the NHS bowel cancer screening programme, which is offered to all men and women aged 60–74 in England and Wales. The NHS bowel cancer screening programme involves testing stool samples to see if there is any blood, which could be a sign of bowel cancer. It does not diagnose bowel cancer but shows whether the person needs further tests.