DefinitionBy Mayo Clinic staff
The fecal occult blood test — also known as FOBT — is a lab test used to check stool samples for hidden (occult) blood.
Occult blood in the stool may indicate colon cancer or polyps in the colon or rectum — though not all cancers or polyps bleed. Typically, occult blood is passed in such small amounts that it can be detected only through the chemicals used in a fecal occult blood test.
If blood is detected through a fecal occult blood test, additional tests may be needed to determine the source of the bleeding. The fecal occult blood test can only detect the presence or absence of blood. The fecal occult blood test doesn't indicate potential sources of bleeding.
- 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.