Fecal occult blood test

A fecal occult blood test looks for blood in a sample of stool. It can find tiny amounts of blood that can't be seen just by looking at the stool. The medical term for this hidden blood is occult blood. Fecal occult blood test is often shortened to FOBT. A fecal occult blood test is one option for colon cancer screening in people who don't have any symptoms. Occult blood in the stool may be a sign of cancer or polyps in the colon or rectum. Polyps are growths of cells that aren't cancers but could become cancers. Not all cancers or polyps bleed.

A fecal occult blood test is used to look for blood in a sample of stool. It's one option for colon cancer screening. It may be used if you have an average risk of colon cancer and no symptoms. The fecal occult blood test is typically done every year. The fecal occult blood test is one of several colon cancer screening tests available. Talk with your healthcare team about which tests might be right for you. The fecal occult blood test is a simple test that requires little or no preparation. Some people prefer this test over the other screening tests because it can be done at home. It doesn't require missing work for a medical appointment. Others may choose this test because it often is less expensive than other tests.

Risks and limitations of the fecal occult blood test include:

To prepare for a fecal occult blood test, you may need to change what you eat and what medicines you take. Various foods, supplements and medicines can affect results of some fecal occult blood tests. The tests may show that blood is present when it isn't, causing a false-positive. Or they may miss blood that's there, causing a false-negative. Before the test your healthcare professional may ask you to avoid: Certain fruits and vegetables. Rare red meat. Certain vitamin supplements, such as vitamin C and iron. Pain relievers, such as aspirin and ibuprofen (Advil, Motrin IB and others). Not all fecal occult blood tests require these preparations. Follow your healthcare professional's instructions.

What you can expect when taking a fecal occult blood test depends on the type of test you take. Each type collects and tests stool samples differently. For best results, follow the instructions that come with your test kit. You may receive a fecal occult blood test kit from your healthcare professional. Or your health professional may arrange to have the kit sent to you by mail. The kit typically includes everything you need to complete the test. The instructions may explain how to catch a bowel movement in the toilet bowl, collect and place a stool sample on a card or in a container, and send the sample to a lab for testing.