A fecal occult blood test checks for hidden
(occult) blood in the stool. You place a small sample of stool on a chemically
treated card. Then a special chemical solution is put on top of
the sample. If the card turns blue, there is blood in the stool
A fecal occult blood test is
done to check for colorectal cancer and other types of gastrointestinal
problems. These include hemorrhoids, anal fissures, and colon polyps, which can cause
blood in the stools.
Before you do a
fecal occult blood test, avoid the following for 2 to 3
days before the test:
Do not do the test during your menstrual period or if you
are having bleeding from hemorrhoids. And don't test a stool sample that has
been in contact with toilet bowl cleaning products that turn the water
You can check for blood in your stool at home. There are different types of home tests
you can use. Make sure to follow the instructions that come with any test.
For most tests, you will use stool samples from three different bowel movements
over three different days.
For any home test, follow
These instructions are for one of the most common
tests used to find blood in the stool.
occult blood test may be used to check for colorectal cancer. But it is never
used to diagnose this condition. If a fecal occult blood test finds blood in
the stool, you may need more tests to find the reason for the bleeding.
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and
call your doctor or nurse call line if you are having problems. It's also a good idea to keep a
list of the medicines you take.
Go to http://www.healthwise.net/ed
Enter W039 in the search box to learn more about "Fecal Occult Blood Test (FOBT): About This Test."
Current as of:
August 9, 2016
Adam Husney, MD - Family Medicine
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