Fecal Occult Blood Test
(FOBT; Stool Occult Blood Test)
by Cynthia M. Johnson, MA
A fecal occult blood test (FOBT) looks for blood in the stool, also known as feces.
Reasons for Test TOP
It may also used to find blood in the stool if you are having belly pain, diarrhea, vomiting, lack of hunger, or other symptoms.
Possible Complications TOP
There are no major problems linked to having this test.
What to Expect TOP
Prior to Test
To improve the accuracy of the test, you may be asked to:
Description of Test
The test is most often done at home.
When you are ready to have a bowel movement, you will set up the kit using the instructions. The kit should allow you to collect 3 samples. Some kits have a disposable container into which you can pass your bowel movement. Other kits give you tissue paper or plastic wrap that you can lay in the toilet to keep your stool from getting into the water.
You can also turn off the water valve to the toilet tank and flush the toilet a couple of times. This will empty most of the water out of the toilet bowl. When ready, pass the bowel movement into the bowl. Collect the sample, then turn the water back on.
Using thin wooden sticks from the kit, you will pick up a small sample of stool. You will then smear the sample onto a special card. If you do not have hemorrhoids, some doctors may allow you to smear the sample onto the card with stool from toilet paper. The card folds over to protect the stool sample.
After Test TOP
You will mail or bring the cards to the clinic or lab. Make sure you have written your name on each card.
How Long Will It Take? TOP
The test should only take a few minutes.
Will It Hurt? TOP
This test will not hurt.
Call Your Doctor TOP
Call your doctor if you have:
If you think you have an emergency, call for emergency medical services right away.
Family Doctor—American Academy of Family Physicians
National Institute on Aging
Canadian Digestive Health Foundation
Colorectal cancer screening. EBSCO DynaMed Plus website. Available at: http://www.dynamed.... Updated May 21, 2018. Accessed July 20, 2018.
Colorectal cancer screening tests. American Cancer Society website. Available at: https://www.cancer.org/cancer/colon-rectal-cancer/detection-diagnosis-staging/screening-tests-used.html. Updated May 30, 2018. Accessed July 20, 2018.
Fecal occult blood test and fecal immunochemical test. Lab Tests Online—American Association for Clinical Chemistry website. Available at: https://labtestsonline.org/tests/fecal-occult-blood-test-and-fecal-immunochemical-test. Updated July 13, 2018. Accessed July 20, 2018.
Last reviewed June 2018 by James Cornell, MD
Last Updated: 7/20/18
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