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Colorectal Cancer Awareness Month - Tests to Find Colorectal Cancer Early

Recommendations for Colorectal Cancer Early Detection

People at average risk

Good Samaritan Hospital Medical Center and the American Cancer Society believe that preventing colorectal cancer (and not just finding it early) should be a major reason for getting tested. Having polyps found and removed keeps some people from getting colorectal cancer. You are encouraged to have tests that have the best chance of finding both polyps and cancer if these tests are available to you and you are willing to have them.

Starting at age 50, men and women at average risk for developing colorectal cancer should use one of the screening tests below:

Tests that find polyps and cancer

  • Flexible sigmoidoscopy every 5 years*
  • Colonoscopy every 10 years
  • Double-contrast barium enema every 5 years*
  • CT colonography (virtual colonoscopy) every 5 years*

Tests that mainly find cancer

  • Guaiac-based fecal occult blood test (gFOBT) every year*,**
  • Fecal immunochemical test (FIT) every year*,**
  • Stool DNA test every 3 years*
*Colonoscopy should be done if test results are positive.
** Highly sensitive versions of these tests should be used with the take-home multiple sample method. A gFOBT or FIT done during a digital rectal exam in the doctor’s office is not enough for screening.

Is a rectal exam enough to screen for colorectal cancer?

In a digital rectal examination (DRE), a health care provider examines your rectum with a lubricated, gloved finger. Although a DRE is often included as part of a routine physical exam, it’s not recommended as a stand-alone test for colorectal cancer. This simple test, which is not usually painful, can find masses in the anal canal or lower rectum. But by itself, it’s not a good test for detecting colorectal cancer because it only checks the lower rectum.

Doctors often find a small amount of stool in the rectum when doing a DRE. But testing this stool for blood with a gFOBT or FIT is not an acceptable way to screen for colorectal cancer. Research has shown that this type of stool exam will miss more than 90% of colon abnormalities, including most cancers.

People at increased or high risk

If you are at an increased or high risk of colorectal cancer, you might need to start colorectal cancer screening before age 50 and/or be screened more often. The following conditions make your risk higher than average:

  • A personal history of colorectal cancer or adenomatous polyps
  • A personal history of inflammatory bowel disease (ulcerative colitis or Crohn’s disease)
  • A strong family history of colorectal cancer or polyps (see Colorectal Cancer Risk Factors)
  • A known family history of a hereditary colorectal cancer syndrome such as familial adenomatous polyposis (FAP) or Lynch syndrome (hereditary non-polyposis colon cancer or HNPCC)