Fecal Occult Blood Test

 

A fecal occult blood test(FOBT) is used as an early screening test for colorectal cancer. It may also be used to diagnose other conditions that cause bleeding in the digestive tract. Sometimes a fecal occult blood test is ordered to evaluate for unexplained anemia.

Preparation of test

For about three days before the test, your doctor may ask you to avoid:

  • Certain fruits and vegetables, including broccoli and turnips
  • Red meat
  • Horseradish
  • Vitamin C supplements
  • Pain relievers, such as aspirin and ibuprofen (Advil, Motrin IB, others)

How to Test

A fecal occult blood test is a noninvasive test that you can perform at home. Your health care provider will give you a kit that includes instructions on how to do the test. There are two main types of fecal occult blood tests: the guaiac smear method (gFOBT) and the immunochemical method (iFOBT or FIT).

For a guaiac smear test (gFOBT), you will most likely need to:

  • Collect samples from three separate bowel movements.
  • For each sample, collect the stool and store in a clean container. Make sure the sample does not mix in with urine or water from the toilet.
  • Use the applicator from your test kit to smear some of the stool on the test card or slide, also included in your kit.
  • Label and seal all your samples as directed.
  • Mail the samples to your health care provider or lab.

For a fecal immunochemical test (FIT), you will most likely need to:

  • Collect samples from two or three bowel movements.
  • Collect the sample from the toilet using the special brush or other device that was included in your kit.
  • For each sample, use the brush or device to take the sample from the surface of the stool.
  • Brush the sample onto a test card.
  • Label and seal all your samples as directed.
  • Mail the samples to your health care provider or lab.

Be sure to follow all the instructions provided in your kit, and talk to your health care provider if you have any questions.

Test Results

Negative result – it means no blood was found in the sample.

Positive result – it means blood was detected in the sample, your doctor will order further exams, such as colonoscopy

 

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.