Colorectal Cancer Prevention and Early Detection

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American Cancer Society recommendations for colorectal cancer early detection

People at average risk

The American Cancer Society believes that preventing colorectal cancer (and not just finding it early) should be a major reason for getting tested. Having their polyps found and removed keeps some people from getting colorectal cancer. Tests that have the best chance of finding both polyps and cancer are preferred if these tests are available to you and you are willing to have them.

Beginning at age 50, both 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 (sDNA) 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. An FOBT or FIT done during a digital rectal exam in the doctor's office is not adequate for screening.

Is a rectal exam enough to screen for colorectal cancer?

In a digital rectal examination (DRE), a doctor examines your rectum with a lubricated, gloved finger. Although a DRE is often included as part of a routine physical exam, it is not recommended as a stand-alone test for colorectal cancer. This simple test, which is not usually painful, can detect masses in the anal canal or lower rectum. By itself, however, it is not a good test for detecting colorectal cancer because its reach is limited.

Doctors often find a small amount of stool in the rectum when doing a DRE. However, simply checking stool obtained this way for bleeding with an FOBT or FIT is not an acceptable method of screening 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 should begin 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 “Risk factors for colorectal cancer”)
  • A known family history of a hereditary colorectal cancer syndrome such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colon cancer (HNPCC)

The table below suggests screening guidelines for those with increased or high risk of colorectal cancer based on specific risk factors. Some people may have more than one risk factor. Refer to the table below and discuss these recommendations with your doctor. Based on your situation, your doctor can suggest the best screening option for you, as well as any changes in the schedule based on your individual risk.

    American Cancer Society Guidelines on Screening and Surveillance for the Early Detection of Colorectal Adenomas and Cancer in People at Increased Risk or at High Risk

    INCREASED RISK – Patients With a History of Polyps on Prior Colonoscopy

    Risk Category


    Recommended Test(s)


    People with small rectal hyperplastic polyps

    Same age as those at average risk

    Colonoscopy, or other screening options at same intervals as for those at average risk

    Those with hyperplastic polyposis syndrome are at increased risk for adenomatous polyps and cancer and should have more intensive follow-up.

    People with 1 or 2 small (less than 1 cm) tubular adenomas with low-grade dysplasia

    5 to 10 years after the polyps are removed


    Time between tests should be based on other factors such as prior colonoscopy findings, family history, and patient and doctor preferences.

    People with 3 to 10 adenomas, or a large (1 cm +) adenoma, or any adenomas with high-grade dysplasia or villous features

    3 years after the polyps are removed


    Adenomas must have been completely removed. If colonoscopy is normal or shows only 1 or 2 small tubular adenomas with low-grade dysplasia, future colonoscopies can be done every 5 years.

    People with more than 10 adenomas on a single exam

    Within 3 years after the polyps are removed


    Doctor should consider possibility of genetic syndrome (such as FAP or HNPCC).

    People with sessile adenomas that are removed in pieces

    2 to 6 months after adenoma removal


    If entire adenoma has been removed, further testing should be based on doctor's judgment.

    INCREASED RISK – Patients With Colorectal Cancer

    Risk Category

    When to Begin

    Recommended Test(s)


    People diagnosed with colon or rectal cancer

    At time of colorectal surgery, or can be 3 to 6 months later if person doesn't have cancer spread that can't be removed

    Colonoscopy to view entire colon and remove all polyps

    If the tumor presses on the colon/rectum and prevents colonoscopy, CT colonoscopy (with IV contrast) or DCBE may be done to look at the rest of the colon.

    People who have had colon or rectal cancer removed by surgery

    Within 1 year after cancer resection (or 1 year after colonoscopy to make sure the rest of the colon/rectum was clear)


    If normal, repeat exam in 3 years. If normal then, repeat exam every 5 years. Time between tests may be shorter if polyps are found or there is reason to suspect HNPCC. After low anterior resection for rectal cancer, exams of the rectum may be done every 3 to 6 months for the first 2 to 3 years to look for signs of recurrence.

    INCREASED RISK – Patients With a Family History

    Risk Category

    Age to Begin

    Recommended Test(s)


    Colorectal cancer or adenomatous polyps in any first-degree relative before age 60, or in 2 or more first-degree relatives at any age (if not a hereditary syndrome).

    Age 40, or 10 years before the youngest case in the immediate family, whichever is earlier


    Every 5 years.

    Colorectal cancer or adenomatous polyps in any first-degree relative aged 60 or older, or in at least 2 second-degree relatives at any age

    Age 40

    Same options as for those at average risk.

    Same intervals as for those at average risk.


    Risk Category

    Age to Begin

    Recommended Test(s)


    Familial adenomatous polyposis (FAP) diagnosed by genetic testing, or suspected FAP without genetic testing

    Age 10 to 12

    Yearly flexible sigmoidoscopy to look for signs of FAP; counseling to consider genetic testing if it hasn't been done

    If genetic test is positive, removal of colon (colectomy) should be considered.

    Hereditary non-polyposis colon
    cancer (HNPCC), or at increased risk of HNPCC based on family history without genetic testing

    Age 20 to 25 years, or 10 years before the youngest case in the immediate family

    Colonoscopy every 1 to 2 years; counseling to consider genetic testing if it hasn't been done

    Genetic testing should be offered to first-degree relatives of people found to have HNPCC mutations by genetic tests. It should also be offered if 1 of the first 3 of the modified Bethesda criteria is met.1

    Inflammatory bowel disease:

    -Chronic ulcerative colitis

    -Crohn's disease

    Cancer risk begins to be significant 8 years after the onset of pancolitis (involvement of entire large intestine), or 12-15 years after the onset of left-sided colitis

    Colonoscopy every 1 to 2 years with biopsies for dysplasia

    These people are best referred to a center with experience in the surveillance and management of inflammatory bowel disease.

1The Bethesda criteria can be found in the "Can colorectal cancer be prevented?" section

Last Medical Review: 10/15/2014
Last Revised: 02/05/2015