Why it's done
By Mayo Clinic staffYour doctor may recommend a fecal occult blood test to:
- Screen for colon cancer. If you're age 50 or older and at average risk of colon cancer, your doctor may recommend a fecal occult blood test every year to screen for colon cancer. In addition, however, you may need other screening tests that allow the doctor to examine the colon directly.
- Evaluate possible causes of unexplained anemia. Anemia is a condition in which there aren't enough healthy red blood cells to carry adequate oxygen to your tissues. Sometimes a fecal occult blood test is used to determine whether gastrointestinal bleeding — such as a bleeding ulcer — is contributing to anemia.
References
- Fecal occult blood test: The test sample. American Association for Clinical Chemistry. http://www.labtestsonline.org/understanding/analytes/fecal_occult_blood/test.html. Accessed April 12, 2011.
- Fletcher RH. Tests for screening for colorectal cancer: Stool tests, radiologic imaging and endoscopy. http://www.uptodate.com/home/index.html. Accessed April 12, 2011.
- Labianca R, et al. Screening and diagnosis for colorectal cancer: present and future. Tumori. 2010;96:889.
- American Cancer Society guidelines for the early detection of cancer. American Cancer Society. http://www.cancer.org/docroot/PED/content/PED_2_3X_ACS_Cancer_Detection_Guidelines_36.asp?sitearea=PED. Accessed April 12, 2011.
- Lieberman D. Progress and Challenges in Colorectal Cancer Screening and Surveillance. Gastroenterology. 2010;138:2115.
- Levin B, et al. Screening and surveillance for the early detection of colorectal cancer and adenomatous polyps, 2008: A joint guideline from the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology. Gastroenterology. 2008;134:1570.
- Doppler JM (expert opinion). Mayo Clinic, Rochester, Minn. June 8, 2011.


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