Other
Faecal Calprotectin Test
A faecal calprotectin test measures a protein in the stool that rises with inflammation in the bowel, helping tell inflammatory bowel disease from IBS.
Quick answer
Faecal Calprotectin Test: what it is and what the results mean
Calprotectin is a protein released by white blood cells when there is inflammation in the gut. A stool test measures its level, which is raised when the bowel lining is inflamed.
- Why it is done: It is used to help distinguish inflammatory bowel disease (such as Crohn’s disease and ulcerative colitis) from non-inflammatory conditions like irritable bowel syndrome, and to monitor known inflammatory bowel disease.
- Understanding results: A low level makes bowel inflammation unlikely and points away from inflammatory bowel disease, often avoiding the need for a colonoscopy.
What it is
Calprotectin is a protein released by white blood cells when there is inflammation in the gut. A stool test measures its level, which is raised when the bowel lining is inflamed.
Why it is done
It is used to help distinguish inflammatory bowel disease (such as Crohn’s disease and ulcerative colitis) from non-inflammatory conditions like irritable bowel syndrome, and to monitor known inflammatory bowel disease.
What to expect
You collect a small stool sample at home in a special container and return it to the laboratory. No special preparation is usually needed, though some medicines can affect the result.
Understanding the results
A low level makes bowel inflammation unlikely and points away from inflammatory bowel disease, often avoiding the need for a colonoscopy. A raised level suggests inflammation and usually prompts further tests such as endoscopy.
Good to know
Risks and limitations
It is a safe, non-invasive test, but it indicates inflammation rather than its exact cause. Some medicines (such as anti-inflammatory painkillers) and infections can raise it, so results are interpreted in context.
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
Faecal Calprotectin Test: frequently asked questions
Can this test tell IBS from inflammatory bowel disease?
It helps. A normal calprotectin makes inflammatory bowel disease unlikely and supports a diagnosis of IBS, while a raised level points to inflammation and usually leads to further investigation.
What can raise faecal calprotectin apart from IBD?
Gut infections and anti-inflammatory painkillers (NSAIDs) can raise it, so a high result is interpreted alongside your symptoms and may be repeated or followed by other tests.
Related tests
Other other investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- Association for Laboratory Medicine / relevant professional body
Building patient-education content for tests or procedures?
We create clear, accurate, referenced medical explainers and decision aids for teams.