Topic Overview

The Canadian Association of Gastroenterology and the Canadian Digestive Health Foundation recommend routine colorectal testing for people age 50 and older who do not have an increased risk for developing colorectal cancer. People with a higher risk, such as people of African descent and people with a strong family history of colon cancer, should be tested sooner. Talk to your doctor about when you should be tested.

The following guidelines are for people older than 50 who do not have an increased risk for colorectal cancer.^{1, 2}

Other tests that may be used to screen for colorectal cancer include:

• Computed tomographic colonography (CTC), also known as a virtual colonoscopy.
• Barium enema.

Some tests for colorectal cancer screening may not be available in all areas. Check with your doctor to find out what tests are used in your area.

For more information on screening tests for colon cancer, see:

Colon Cancer: Which Screening Test Should I Have?

You will need to begin routine testing earlier than age 50 and have it more frequently if you have an increased risk for colorectal cancer. You have an increased risk if you:

• Already have been diagnosed with colorectal cancer.
• Have a first-degree relative (parent, brother, sister, or child) with an adenomatous polyp or colorectal cancer.
• Are of African descent.
• Have had adenomatous polyps removed from your colon. This type of polyp is more likely to turn into cancer, but the risk is still very low.
• Have inflammatory bowel disease, such as ulcerative colitis or Crohn's disease.
• Have a rare inherited polyp syndrome, such as FAP or Lynch syndrome (HNPCC).
• Have had radiation treatments to the abdomen or pelvis.

What to think about

Virtual colonoscopy uses X-rays and computers to take two- or three-dimensional pictures of the interior lining of your large intestine. It may be used as a test for people who do not have an increased risk for colon cancer or for people who cannot have a colonoscopy. For people who have an increased risk for colon cancer, conventional colonoscopy may be better because it permits tissue biopsies or polyp removal. Virtual colonoscopy is not widely available in most parts of Canada, and the cost may not be covered by provincial health plans or private health insurance.³