Stool Tests for Colorectal Cancer

Since colorectal cancers do not bleed all the time, FOBT and FIT/iFOBT tests are done over several days on different stool samples. This increases the chance of finding blood in your stool if it exists. A stool DNA test requires only one sample.

You may need to avoid certain foods for 2 to 3 days before the test. This depends on what kind of stool test you use. If you aren't sure, ask your doctor.

Do not do the stool tests during your menstrual period or if you have active bleeding from hemorrhoids. Also, do not test a stool sample that has been in contact with toilet bowl cleaning products that turn the water blue.

Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form (What is a Reference PDF Opens New Window document?).

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