Lab test · Cancer screening
Fecal immunochemical test (FIT)
A FIT test checks stool for hidden blood and is one of the recommended ways to screen for colorectal cancer. How it works and what happens after a positive result.
Written by LON6EVITY Editorial Team · Last updated
What it detects
MedlinePlus explains that fecal occult blood tests, including the fecal immunochemical test (FIT), look for small amounts of blood in stool that cannot be seen, which can be a sign of polyps or colorectal cancer.
Role in screening
The USPSTF lists yearly FIT among the recommended stool-based screening options for adults in the recommended age range. It is done at home with a sample kit.
After a positive result
A positive FIT does not mean cancer; bleeding has many causes. It should be followed by a colonoscopy.
Factors that can affect the result
- Bleeding from other causes
- Correct sample collection
Questions people commonly ask
- Do I need to change my diet before FIT?
- Unlike older guaiac tests, FIT generally does not need diet restrictions — follow your kit's instructions.
Related topics
Keep your health results in one place
What does this mean for your own health data? Log your results, follow trends over time and bring an organised summary to your next doctor's appointment.
Sources
- Fecal Occult Blood Test (FOBT). MedlinePlus, U.S. National Library of Medicine.
- Colorectal Cancer: Screening. U.S. Preventive Services Task Force, 2021.