Stool Test Options

Which stool test is right for you?

A stool test is used to detect the presence of blood or other gastrointestinal abnormalities, such as colon cancer, inflammatory bowel disease, hemorrhoids, anal fissures or infections.

Man looking at a medical chart and talking with his doctor
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There are two main types of stool tests to choose from. A fecal occult blood test (FOBT) detects the presence of blood in your feces. The second type, a stool DNA test, detects the presence of genetic material from polyps and cancerous tumors.

FOBT Stool Tests

FOBTs use a chemical reaction to check for the presence of blood in your stool. They may be performed in a healthcare provider's office or at home. Guaiac FOBTs (gFOBTs) are the oldest type of stool test; they're the least accurate and the cheapest to buy over-the-counter.

Immunochemical FOBTs (iFOBTs), also known as fecal immunochemical tests (FITs), are newer and more sensitive options for detecting blood in stool, but they can also be more expensive if the test isn't covered by insurance. For example, iFOBTs can cost about $20 to $50. The iFOBT stool test detects the presence of hemoglobin, a protein found in blood.


Rather than looking for hidden blood, sDNA tests, also known as FIT-DNA tests, look for traces of DNA (genetic material) shed by polyps and/or colorectal tumors. This is the most sensitive stool test currently available.

Cologuard is the most common stool test used for this type of screening. The Cologuard test is able to detect blood in a sample of stool as well as 10 different associated with colon cancer (including NDRG4BMP3, and KRAS mutations).

It's important to note that stool testing is only an effective colon cancer screening option when used in combination with other methods. If your stool test comes back positive, the next step is to make an appointment with your healthcare provider, who will probably order a colonoscopy or similar test.

Frequently Asked Questions

  • Are there different types of stool test?

    Yes, there are different types of stool test.

    • Fecal Immunochemical Test (FIT): This test checks to see if any blood found in stool originated in the lower intestines. It only requires one stool sample.
    • Fecal Occult Blood Test (FOBT): This test checks for blood that is hidden in the stool. Unlike the FIT, the FOBT cannot discern where blood came from. Three different stool samples are required for this test.
    • Stool DNA Testing: A newer type of test, it checks the DNA contained in stool to detect colorectal cancer. Only one stool sample is needed for this test.
  • What defines an abnormal stool sample?

    An abnormal stool sample might contain blood, viruses, fungi, harmful bacteria, undigested meat fibers, parasites, mucus, pus, rotaviruses, or high levels of fat. The stool could also be an unusual color, such as red, green, yellow, white, or black. The presence of these factors might not always indicate something is wrong, but it can help a doctor understand potential health issues.

  • Are there stool tests to check for parasites?

    Yes, an ova and parasite test (O&P) is a stool test that checks for parasites. It can help figure out if parasites are the cause of diarrhea, cramping, excessive gas, loose stool, watery stool, or another abdominal condition. Multiple stool samples taken on different days may be needed for this test.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Cancer Society. Colorectal cancer screening tests.

  2. Naber SK, Knudsen AB, Zauber AG, et al. Cost-effectiveness of a multitarget stool DNA test for colorectal cancer screening of Medicare beneficiaries. Goel A, ed. PLoS ONE. 2019;14(9):e0220234. doi:10.1371/journal.pone.0220234

  3. Cancer Treatment Centers of America. Stool Tests for Colorectal Cancer.

  4. University of Michigan Health: Michigan Medicine. Stool Analysis: Results.

  5. Centers for Disease Control and Prevention (CDC). Diagnosis of Parasitic Diseases.