If bowel cancer is much more common at 70 than at 30, it seems logical that the same result should be read differently depending on who produced it. A figure of 25 in a 68-year-old and a figure of 25 in a 32-year-old surely do not mean the same thing.
It is a good question, and the answer is more interesting than a straight yes or no.
The short answer
No. The threshold is the same for everyone.
There is not currently enough evidence to justify using different cut-offs by age, sex or ethnicity. Guidance is clear that a stool test can and should be used to assess adults of all ages with bowel symptoms, against the same number.
Why that is deliberate rather than lazy
Two things are being confused when people ask this, and separating them helps.
The test measures blood. How much blood is in your sample is a fact about your bowel, not about your demographics. A reading of 25 means the same amount of blood regardless of who you are.
The likelihood that blood means cancer does vary. Bowel cancer is less common in younger people, so a raised result in a 32-year-old is statistically less likely to be cancer than the same result in a 68-year-old.
But that second point is an argument for interpreting your result in context, which is what a doctor does. It is not an argument for moving the line at which the test flags something. Raising the threshold for younger people would mean deliberately choosing to detect fewer of their cancers, in the age group where cancers are rising fastest and are already diagnosed later.
Why this matters if you are under 50
There is a version of this reasoning that gets used against younger patients, and it is worth naming.
“You are too young for this to be anything serious” is a statement about population averages applied to an individual. It is often true and occasionally catastrophic. Around 1 in 20 UK bowel cancer cases occur in people under 50, and younger patients frequently report multiple GP visits before being referred.
The fact that guidance sets no age-adjusted threshold is quietly important here. It means a raised result in a 30-year-old is a raised result. Nobody is entitled to discount it because of the birthday on the form.
Where age does legitimately come in
To be balanced about it, age is not irrelevant.
It affects how urgently things are investigated, what else is considered alongside the bowel, and how a borderline figure is weighed against everything else in the picture. National referral criteria do include age in some of their combinations of symptoms.
The distinction is between age as context and age as a filter. Context is good medicine. A filter that stops a younger person’s raised result being taken seriously is not.
What this means for your result
Your number means what it means. Interpreting it properly involves your age, your symptoms, your family history and anything else relevant, which is a conversation rather than a calculation.
That is the reason we include a consultation with every result rather than sending a figure and leaving you to look up what it means for someone your age. The figure is objective. What to do about it is not.
References
- Monahan KJ, Davies MM, Abulafi M, et al. Faecal immunochemical testing (FIT) in patients with signs or symptoms of suspected colorectal cancer: a joint guideline from ACPGBI and BSG. Gut 2022;71:1939 to 1962.
- National Institute for Health and Care Excellence. Suspected cancer: recognition and referral. NG12.
- Cancer Research UK. Bowel cancer statistics.
- Bowel Cancer UK. Never Too Young report.
Figures are drawn from the sources above. Framing and commentary are the author’s own. Last reviewed August 2026.