Three Types of Colorectal Cancer Screenings

There is more than one way to determine the presence of colorectal cancer. Please see the chart below to understand the types of visual screening options so you can be prepared to talk with your doctor about which is best for you.

Screening Type	Colonoscopy	Sigmoidoscopy	Virtual Colonoscopy (Computed Tomography Colonography)
How It Works	A thin tube with a light and a lens for viewing is inserted into the entire length of the colon. The doctor can see and remove polyps or take tissue samples.	The same process as a colonoscopy but focuses only on the lower (sigmoid) colon.	A computer combines a series of x-rays of the colon that may show polyps or unusual activity.
Sedation	Yes	Not typical	No
Benefits	Complete picture of colon Remove polyps for biopsy May find other diseases Every 10 years if normal results	Fairly quick Full bowel prep may not be necessary Does not require a specialist Every 5 years if normal results	Fairly quick Complete picture of colon Every 5 years if normal results
Limitations	Can miss small polyps Cost Need a driver due to sedation Small risk of bleeding, bowel tear or infection May miss a day of work	Only reviews about 1/3 of colon area Can miss small polyps Can’t remove all polyps May be uncomfortable without sedation If abnormal, need a follow up colonoscopy	Can miss small polyps Can’t remove polyps during test Small radiation exposure If abnormal, need a follow up colonoscopy New test, may have insurance coverage issues

Sources:
National Cancer Institute
American Cancer Society