BOB体育

Skip to main content

Colon cancer screening

Definition

Colon cancer screening can detect polyps and early cancers in the large intestine. This type of screening can find problems that can be treated before cancer develops or spreads. Regular screenings may reduce the risk for death and complications caused by colorectal cancer.

Patient Education Video: Colon cancer screening

Alternative Names

Screening for colon cancer; Colonoscopy - screening; Sigmoidoscopy - screening; Virtual colonoscopy - screening; Fecal immunochemical test; Stool DNA test; sDNA test; Colorectal cancer - screening; Rectal cancer - screening

Information

SCREENING TESTS

There are several ways to screen for colon cancer.

Stool test:

  • Polyps in the colon and small cancers can cause small amounts of bleeding that cannot be seen with the naked eye. But blood can often be found in the stool.
  • This method checks your stool for blood.
  • A common test used is the fecal occult blood test (gFOBT). Two other tests are called the fecal immunochemical test (FIT) and stool DNA test (sDNA) commonly known as Cologuard.

Sigmoidoscopy:

  • This test uses a small flexible scope to view the lower part of your colon. Because the test only looks at the last one third of the large intestine (colon), it may miss some cancers that are higher in the large intestine.
  • Sigmoidoscopy and a stool test may be used together.

Colonoscopy:

  • A colonoscopy is similar to a sigmoidoscopy, but the entire colon can be viewed.
  • Your health care provider will give you the steps for cleansing your bowel. This is called bowel preparation.
  • During a colonoscopy, you receive medicine to make you relaxed and sleepy.
  • Sometimes, CT scans are used as an alternative to a regular colonoscopy. This is called a virtual colonoscopy.
Colonoscopy
There are 3 basic tests for colon cancer; a stool test (to check for blood), sigmoidoscopy (inspection of the lower colon), and colonoscopy (inspection of the entire colon). All 3 are effective in catching cancers in the early stages, when treatment is most beneficial.

Other test:

  • Capsule endoscopy involves swallowing a small, pill-sized camera that takes a video of the inside of your intestines. The method is being studied, so it is not recommended for standard screening at this time.
Capsule endoscopy
Capsule endoscopy is a test procedure in which a camera inside a small capsule takes pictures of the lining of your digestive system. The capsule is about the size of a large vitamin pill. After swallowing it, the capsule travels the length of your digestive system and transmits images to a wearable recorder.

SCREENING FOR AVERAGE-RISK PEOPLE

There is not enough evidence to say that any one screening method is best. Colonoscopy is the most thorough but also has the highest risk. Talk to your provider about which test is right for you.

All adults should have a colon cancer screening test starting at age 45.

Screening options for people with an average risk for colon cancer:

  • Colonoscopy every 10 years starting at age 45
  • gFOBT or FIT every year (colonoscopy is needed if results are positive)
  • sDNA-FIT every 1 to 3 years (colonoscopy is needed if results are positive)
  • Flexible sigmoidoscopy every 5 years or every 10 years plus stool testing with FIT done every year
  • CT colonography (virtual colonoscopy) every 5 years

SCREENING FOR HIGHER-RISK PEOPLE

People with certain risk factors for colon cancer may need earlier (before age 45) or more frequent testing.

More common risk factors are:

  • A family history of inherited colorectal cancer syndromes, such as familial adenomatous polyposis (FAP) or hereditary nonpolyposis colorectal cancer (HNPCC).
  • A strong family history of colorectal cancer or polyps. This usually means close relatives (parent, sibling, or child) who developed these conditions younger than age 60.
  • A personal history of colorectal cancer or polyps.
  • A personal history of long-term (chronic) inflammatory bowel disease (for example, ulcerative colitis or Crohn disease).

Screening for these groups is more likely to be done using colonoscopy.

Gallery

Colonoscopy
There are 3 basic tests for colon cancer; a stool test (to check for blood), sigmoidoscopy (inspection of the lower colon), and colonoscopy (inspection of the entire colon). All 3 are effective in catching cancers in the early stages, when treatment is most beneficial.
Colonoscopy
There are 3 basic tests for colon cancer; a stool test (to check for blood), sigmoidoscopy (inspection of the lower colon), and colonoscopy (inspection of the entire colon). All 3 are effective in catching cancers in the early stages, when treatment is most beneficial.
Colonoscopy
There are 3 basic tests for colon cancer; a stool test (to check for blood), sigmoidoscopy (inspection of the lower colon), and colonoscopy (inspection of the entire colon). All 3 are effective in catching cancers in the early stages, when treatment is most beneficial.
Fecal occult blood test
A fecal occult blood test is a noninvasive test that detects the presence of hidden blood in the stool. Blood in the stool that is not visible is often the first, and in many cases the only, warning sign that a person has colorectal disease, including colon cancer.
Capsule endoscopy
Capsule endoscopy is a test procedure in which a camera inside a small capsule takes pictures of the lining of your digestive system. The capsule is about the size of a large vitamin pill. After swallowing it, the capsule travels the length of your digestive system and transmits images to a wearable recorder.

References

Garber JJ, Chung DC. Colonic polyps and polyposis syndromes. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 126.

National Cancer Institute website. Colorectal cancer screening (PDQ) -- health professional version. . Updated June 29, 2023. Accessed July 16, 2023.

Rex DK, Boland CR, Dominitz JA, et al. Colorectal cancer screening: recommendations for physicians and patients from the U.S. Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterol. 2017;112(7):1016-1030. PMID: 28555630 .

US Preventive Services Task Force website. Final recommendation statement. Colorectal cancer: screening. . Published May 18, 2021. Accessed July 15, 2023.

Wolf AMD, Fontham ETH, Church TR, et al. Colorectal cancer screening for average-risk adults: 2018 guideline update from the American Cancer Society. CA Cancer J Clin. 2018;68(4):250-281. PMID: 29846947 .

Last reviewed July 30, 2022 by Michael M. Phillips, MD, Emeritus Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Internal review and update on 07/16/2023 by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team..

Related specialties

Aftercare and more

Our locations

Our Experts

Community and Patient Programs: Colon cancer screening

Our community and patient programs provide great value to patients, families and loved ones. People can find support, educational materials, expert consultants and more. In most instances, these programs are offered free of charge.

  • Adult Cancer Survivorship Program

    Improves health and quality of life for long-term cancer survivors.

  • An educational and networking event that brings together cancer patients, survivors, caregivers and health care professionals.

  • Helps individuals access high-quality cancer screening, prevention and treatment services.

  • Helps bridge the gap between community members and resources available to them, including health screenings, classes and other services.

  • Social Workers for Cancer Patients

    Can assist you through the treatment process in a number of practical and supportive ways.

News and Patient Stories: Colon cancer screening

More Colon cancer screening stories