While colonoscopy and stool tests are the most common tests used to look for colon cancer, there are other tests that can be done. Keep in mind that the tests below may not be available in all parts of the U.S. Click on the two tabs to learn more.

How it works: CT scanner takes 3D X-rays of your colon.

Steps:

1. You will need to cleanse the colon of poop so the doctor can better see inside your colon. To do so, you will be on a clear liquid diet and drink a bowel prep (ie, laxative) the day before the test. You will also drink a contrast dye the day before and morning of the test.
2. On the day of the test, you go to a radiology center.
3. To take better pictures, the colon is inflated by pumping air into it using a small flexible tube that is put in your rectum.
4. The CT scanner takes 3D X-rays of your colon.
5. The colon CT scan takes about 10-15 minutes, and you can expect to be in the radiology center for about 1-2 hours.

How often you do the test:

• Repeat every 5 years.
• If the test comes back positive (ie, images show a possible colon cancer or polyp), you'll need to do a follow-up colonoscopy to confirm the results.

Risks: Colon CT scan is a very safe procedure. However, you are exposed to small amounts of radiation. Also, the doctor may see abnormal findings outside the colon (eg, kidneys, liver, pancreas). Depending on what is seen, other tests may need to be done.