Colorectal Cancer Screening: Care Instructions

Overview

Colorectal cancer occurs in the colon or rectum. That's the lower part of your digestive system. It often starts in small growths called polyps in the colon or rectum. Polyps are usually found with screening tests. Depending on the type of test, any polyps found may be removed during the tests.

Colorectal cancer usually does not cause symptoms at first. But regular tests can help find it early, before it spreads and becomes harder to treat.

Your risk for colorectal cancer gets higher as you get older. Experts recommend starting screening at age 45 for people who are at average risk. Talk with your doctor about your risk and when to start and stop screening. You may have one of several tests.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

What are the main screening tests for colorectal cancer?

The screening tests include:

• Stool tests. These include the guaiac fecal occult blood test (gFOBT), the fecal immunochemical test (FIT), and the combined fecal immunochemical test and stool DNA test (FIT-DNA). These tests check stool samples for signs of cancer. If your test is positive, you will need to have a colonoscopy.
• Sigmoidoscopy. This test lets your doctor look at the lining of your rectum and the lowest part of your colon. Your doctor uses a lighted tube called a sigmoidoscope. This test can't find cancers or polyps in the upper part of your colon. In some cases, polyps that are found can be removed. But if your doctor finds polyps, you will need to have a colonoscopy to check the upper part of your colon.
• CT colonography (also called virtual colonoscopy). This test lets your doctor look at the inside of your colon using a series of pictures that are taken outside of your body. If the doctor sees a problem during the test, such as a polyp or abnormal tissue, you will need to have a colonoscopy so that a biopsy of the polyp or tissue can be done.
• Colonoscopy. This test lets your doctor look at the lining of your rectum and your entire colon. The doctor uses a thin, flexible tool called a colonoscope. It can also be used to remove polyps or get a tissue sample (biopsy).

A newer test is also available that look for signs of colorectal cancer in a blood sample. This test may not be covered by insurance.

Who should be screened for colorectal cancer?

Experts recommend starting screening at age 45 for people who are at average risk. People at higher risk, such as those with a family history of colorectal cancer, may need to be tested sooner and more often than people at average risk. Talk with your doctor about your risk, when to start and stop screening, and how often to screen.

How often you need screening also depends on the type of test you get:

• Stool tests: Every year for FIT or gFOBT or every 1 to 3 years for FIT-DNA.
• Tests that look inside the colon: Every 5 to 10 years for colonoscopy or every 5 years for sigmoidoscopy and CT colonography. (If you do the FIT test every year, you can get a sigmoidoscopy every 10 years.)

Talk to your doctor about which test is best for you and when to be tested.

When should you call for help?

Watch closely for changes in your health, and be sure to contact your doctor if:

• You have any changes in your bowel habits.
• You have any problems.