Bowel Cancer Screening Test

FIT stands for faecal immunochemical test. It detects human haemoglobin, the protein in red blood cells, in a small stool sample, at levels far too low to see. Bowel cancers and the polyps that can become cancer tend to bleed slightly, so hidden blood in the stool is an early signal worth investigating. It is the test used in the NHS bowel cancer screening programme and by GPs to decide who needs a colonoscopy. Ours is the quantitative version, which gives an actual level rather than just positive or negative.

Screening starts with a FIT test on a stool sample, at home. If it finds blood above the threshold, the next step is a colonoscopy, a camera examination of the bowel, which is the test that confirms or rules out cancer and removes any polyps found. Blood tests cannot detect bowel cancer reliably, though a full blood count can show the anaemia that bleeding causes. If you have symptoms such as a persistent change in bowel habit, blood in your stool, unexplained weight loss or abdominal pain, see a GP rather than screening yourself.

No. Most positive FIT results are not cancer. In NHS screening, only around one in ten people with a positive result is found to have bowel cancer at colonoscopy; many others have polyps, which are removed before they can become cancer, and some have haemorrhoids, inflammation or no cause found. A positive result means you should have a colonoscopy, and your GP report will explain how to arrange one through your GP, who will refer you on the urgent pathway.

A single FIT test detects roughly 70 to 80 percent of bowel cancers at the NHS threshold, and a higher proportion at the lower threshold the NHS adopted in 2026. It is less good at detecting polyps, which bleed less. Because a negative result cannot rule bowel cancer out completely, screening is repeated every two years, and symptoms should always be investigated whatever the result. Testing more often than the NHS, for example annually if you have a family history, increases the chance of catching a cancer early.

Our test reports the amount of haemoglobin in micrograms per gram of stool. The NHS screening programme uses a threshold of 80 micrograms per gram to trigger a colonoscopy referral, lowered from 120 in 2026; GPs investigating symptoms use a much lower threshold of 10. Your GP report interprets your number against these thresholds. The higher the number, the more likely a significant finding, but any level above the threshold should be investigated.

Yes. Bleeding haemorrhoids, anal fissures, menstrual blood and blood in the urine can all cause a positive result, which is why the kit instructions ask you not to collect a sample during or within three days of a period, or while haemorrhoids are bleeding. If you have a positive result and known haemorrhoids, the result should still be followed up rather than assumed to be the haemorrhoids, because both can be present.

NHS screening invites everyone aged 50 to 74 in England every two years, and stops at 74 because the balance of benefit and harm changes with age, though you can request a kit beyond 74. A private FIT is useful if you are under 50, especially with a parent, sibling or child who has had bowel cancer, which more than doubles your risk; if you are between NHS rounds and want reassurance; or if you are over 74 and want to continue. Around one in fifteen bowel cancers is diagnosed in people under 50, and rates in younger adults are rising.

Yes. Order this kit online and it is posted to your home with everything you need: a collection device, a sample tube, instructions and a prepaid return envelope. Collect a small sample, seal it, post it back the same day if you can, and your result and GP report are emailed within 5 to 7 working days. No appointment or GP referral is needed.

Catch a small amount of stool on the paper or device provided, dip the probe from the sample tube into it so the grooves are covered, put the probe back in the tube and click it shut. That is the whole sample; a few milligrams is enough. Write the date on the tube and post it back the same day. Do not collect during or within three days of a period, and stop excess alcohol, aspirin or anti-inflammatories 48 hours before if you can, as they can irritate the gut lining and cause minor bleeding. No dietary restrictions are needed.

Not reliably. There is no routine blood test for bowel cancer. A full blood count can show iron-deficiency anaemia, which is a recognised sign of bleeding from the bowel and a reason GPs refer for investigation, and multi-cancer blood tests such as our TruCheck screen for tumour cells from many cancers including colorectal. But the stool FIT test remains the standard screening test, and colonoscopy the standard diagnostic test.

Results are emailed within 5 to 7 working days of your sample reaching the laboratory, with a GP report that gives your haemoglobin level, what it means against the NHS thresholds and what to do next. If the result is positive, the report explains how to get an urgent referral for colonoscopy through your GP.

A persistent change in bowel habit lasting more than three weeks, blood in your stool or from your bottom, unexplained weight loss, tiredness or breathlessness from anaemia, and persistent abdominal pain, bloating or a lump. Many people with early bowel cancer have no symptoms, which is why screening exists; but if you have any of these, see a GP now rather than waiting for a screening result.