Fecal Occult Blood Test
(FOBT; Stool Occult Blood Test)
by Amy Scholten, MPH
A fecal occult blood test (FOBT) is a test to detect the presence of blood in the stool, also known as feces.
Reasons for Test TOP
It may also used to detect blood in the stool if you are having abdominal pain, diarrhea, vomiting, decreased appetite, or other symptoms.
Possible Complications TOP
There are no major complications associated with this test.
What to Expect TOP
Prior to Test
To avoid a false positive result or an abnormal test, you may be asked to do the following prior to the test:
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 according to the instructions. The kit should allow you to collect 3 samples of stool. Some kits provide a disposable container into which you can pass your bowel movement. Other kits provide you with tissue paper or plastic wrap that you can lay in the toilet to keep your stool sample from sinking into the water.
Another option is to turn off the water valve to the toilet tank and flush the toilet a couple of times to 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 supply back on to allow for flushing.
Using thin wooden sticks provided with 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 deliver 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 any of the following occur:
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 February 5, 2018. Accessed March 14, 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 August 22, 2017. Accessed March 14, 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 March 14, 2018. Accessed March 14, 2018.
Last reviewed March 2018 by EBSCO Medical Review Board Marcie L. Sidman, MD
Last Updated: 3/14/2018
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