Screening
FIT Test
A FIT test detects tiny amounts of blood in the stool that cannot be seen, used in bowel cancer screening and to assess bowel symptoms.
Quick answer
FIT Test: what it is and what the results mean
The faecal immunochemical test (FIT) detects human blood (haemoglobin) in a small stool sample. Hidden blood can be an early sign of bowel cancer or polyps, so the test helps identify who needs further investigation.
- Why it is done: It is used in the national bowel cancer screening programme for people in the eligible age range, and to help assess people with bowel symptoms to decide who should be referred for a colonoscopy.
- Understanding results: A negative result means no significant blood was detected and lowers the likelihood of bowel cancer, though screening is repeated periodically.
What it is
The faecal immunochemical test (FIT) detects human blood (haemoglobin) in a small stool sample. Hidden blood can be an early sign of bowel cancer or polyps, so the test helps identify who needs further investigation.
Why it is done
It is used in the national bowel cancer screening programme for people in the eligible age range, and to help assess people with bowel symptoms to decide who should be referred for a colonoscopy.
What to expect
You collect a tiny stool sample at home using the kit provided and post it to the laboratory. It is simple, private and needs no dietary preparation, unlike older blood-in-stool tests.
Understanding the results
A negative result means no significant blood was detected and lowers the likelihood of bowel cancer, though screening is repeated periodically. A positive result does not mean cancer but prompts further tests, usually a colonoscopy.
Good to know
Risks and limitations
It is safe and non-invasive but is a screening tool, not a diagnosis. It can miss some cancers and give positive results from non-cancerous bleeding (such as piles), so follow-up tests are important.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
FIT Test: frequently asked questions
Does a positive FIT test mean I have bowel cancer?
No. It means blood was detected, which has many causes including piles and polyps. A positive result leads to further tests, usually a colonoscopy, to find the cause.
Why is FIT used for screening?
It can detect bowel cancer and large polyps early, before symptoms appear, when treatment is most effective. Regular screening reduces deaths from bowel cancer.
Related tests
Other screening investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- Association for Laboratory Medicine / relevant professional body
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