Colon-Cancer Screenings: Weighing the Options

Editor’s note: If you ever thought getting a colonoscopy was the only way to screen for colon cancer, you’re wrong. Here, the experts from the Mayo Clinic explain what the choices are:

Make sure that you’re comfortable with the colon cancer screening test your doctor recommends. If your doctor specializes in a particular test but you’d rather have another test, express your wishes. If necessary, your doctor might offer a referral to someone trained in the test with which you feel most comfortable.


Your risk of colon cancer might influence your choice of screening tests. For example, your doctor might recommend colonoscopy as the screening tool of choice, likely at frequent intervals, if you:

Have a personal history of colon cancer or precancerous polyps

Have a parent, sibling or child who’s had colon cancer

Carry a gene for a hereditary colon cancer syndrome

Have a history of inflammatory bowel disease, such as ulcerative colitis or Crohn’s disease


Here’s an overview of the most common colon cancer screening tests.


A colonoscopy is an exam used to detect changes or abnormalities in the large intestine and rectum. A long, flexible tube (colonoscope) is inserted into the rectum. A tiny video camera at the tip of the tube allows the doctor to view the inside of the entire colon.

Pros. Colonoscopy is generally considered the gold standard for colon cancer screening. Polyps or other types of abnormal tissue can be removed through the scope during the exam. Tissue samples (biopsies) can be taken as well. The exam typically takes about 30 to 60 minutes.

Cons. The exam might not detect all small polyps and cancers. You might need to adjust your usual medications before the exam. Typically, you can’t eat solid food the day before the exam and you’ll need to use laxatives or another product to empty your colon. Sedation is generally recommended. Rare complications may include bleeding from the site where a biopsy was taken or a polyp or other abnormal tissue was removed, or a tear in the colon or rectum wall. Cramping or bloating might occur after the exam. Since the sedative can take hours to wear off, you’ll need to arrange for someone to drive you home.

CT colonography (virtual colonoscopy)

CT colonography, also known as virtual colonoscopy, is an exam used to detect changes or abnormalities in the large intestine and rectum. During this exam, an imaging technique known as computerized tomography (CT) is used to produce cross-sectional images of the abdominal organs. To help create clear images, a small tube (catheter) is placed inside your rectum to fill your colon with air or carbon dioxide.

Pros. Unlike traditional colonoscopy, CT colonography doesn’t require sedation or the insertion of a scope into the colon. The exam typically takes about 10 minutes.