Key points
- FIT is a home stool test that looks for hidden human blood. It is used in NHS bowel screening and by GPs to assess bowel symptoms.
- Your result is a number in µg/g. For a GP symptom test, 10 µg/g or more leads to an urgent referral. Screening uses a higher cut-off (80 µg/g, with England moving from 120 to 80).
- A positive FIT does not mean cancer, but it does mean the bowel needs examining, usually by colonoscopy.
- A negative FIT is reassuring but not a guarantee. Ongoing symptoms still need review.
- Piles can cause a positive FIT, but they cannot be assumed to be the cause.
FIT test guides
Each guide answers one question in depth, with the latest NICE and NHS guidance and named sources.
What is a stool FIT test?
FIT stands for faecal immunochemical test. It is a home stool test that detects tiny amounts of human blood that cannot be seen. It is used in NHS bowel cancer screening and by GPs to decide who with bowel symptoms needs urgent investigation.
Read the full guide: The FIT test explained
What does my FIT number mean?
Your number is the amount of blood found in the sample, in micrograms of haemoglobin per gram of stool (µg/g). If your GP requested the test because of symptoms, 10 µg/g or more leads to an urgent referral. NHS bowel screening uses a higher cut-off of 80 µg/g in Scotland and Wales, and England is moving from 120 to 80 µg/g.
Read the full guide: What does my FIT number mean?
Does a positive FIT mean cancer?
No. Most people with a positive FIT do not have cancer. Polyps, piles and inflammation can all cause a positive result. But a positive FIT always needs the bowel examined, usually by colonoscopy, because that is how the minority of serious causes are found early.
Read the full guide: Positive FIT test: what happens next?
Negative FIT but still have symptoms?
Not always. A negative FIT makes bowel cancer much less likely, but it does not rule it out and it does not test for many other causes of bowel symptoms. Symptoms that carry on or get worse should be reviewed, and your GP can still refer you.
Read the full guide: Negative FIT but still have symptoms?
Can piles cause a positive FIT?
Yes. Bleeding piles can make a FIT positive. Because piles are common and often exist alongside polyps or cancer, having piles does not explain a positive result on its own, so the bowel still needs to be examined.
Read the full guide: Can piles cause a positive FIT test?
When not to wait for a FIT result
If you have heavy bleeding, black stools, severe abdominal pain or feel faint, seek urgent medical help (call 999 or go to A&E). A FIT test is not needed to act on these symptoms.
Frequently asked questions about the FIT test
What is a stool FIT test?
FIT stands for faecal immunochemical test. It is a home stool test that detects tiny amounts of human blood that cannot be seen. It is used in NHS bowel cancer screening and by GPs to decide who with bowel symptoms needs urgent investigation.
What does my FIT number mean?
Your number is the amount of blood found in the sample, in micrograms of haemoglobin per gram of stool (µg/g). If your GP requested the test because of symptoms, 10 µg/g or more leads to an urgent referral. NHS bowel screening uses a higher cut-off of 80 µg/g in Scotland and Wales, and England is moving from 120 to 80 µg/g.
Does a positive FIT test mean I have bowel cancer?
No. Most people with a positive FIT do not have cancer. Polyps, piles and inflammation can all cause a positive result. But a positive FIT always needs the bowel examined, usually by colonoscopy, because that is how the minority of serious causes are found early.
If my FIT is negative, can I stop worrying about my symptoms?
Not always. A negative FIT makes bowel cancer much less likely, but it does not rule it out and it does not test for many other causes of bowel symptoms. Symptoms that carry on or get worse should be reviewed, and your GP can still refer you.
Can piles cause a positive FIT test?
Yes. Bleeding piles can make a FIT positive. Because piles are common and often exist alongside polyps or cancer, having piles does not explain a positive result on its own, so the bowel still needs to be examined.
How quickly can I have a colonoscopy after a positive FIT privately?
Usually within days of your consultation with Mr Papettas at Nuffield Health Warwickshire Hospital, Leamington Spa. Self-paying patients can self-refer without a GP letter; insured patients need authorisation from their insurer first.
Written and medically reviewed by Mr Trif Papettas FRCS, Consultant Colorectal and General Surgeon, Leamington Spa, Warwickshire. Last reviewed 26 October 2026. Next review due October 2027, or sooner if NICE or NHS England guidance on FIT changes. This information does not replace advice from your own doctor.