Faecal calprotectin is a protein that white blood cells release into your bowel when it is inflamed. A stool test measures how much is present. Doctors use it to help tell inflammatory bowel disease (IBD) from irritable bowel syndrome (IBS), and to check IBD over time, according to MedlinePlus.
Below we explain why doctors ask for the test, what a normal or high level means, what else can raise it, how to give the sample and what happens next.
What does a calprotectin test show?
It shows whether there is inflammation in your bowel. It does not show where the inflammation is or what causes it. The more calprotectin there is, the more inflammation there is likely to be (MedlinePlus). This makes it a useful first step before more invasive tests.
Why would a doctor ask for a calprotectin test?
The main reason is to tell IBD from IBS. Both can cause belly pain, bloating and diarrhoea. IBD, which includes Crohn’s disease and ulcerative colitis, inflames the bowel. IBS does not. So calprotectin is usually raised in IBD and normal in IBS.
In the UK, NICE recommends the test for adults with new lower bowel symptoms, when cancer is not suspected and a specialist referral is being considered. It is also used for children with suspected IBD who have been referred to a specialist (NICE). People who already have IBD may have the test to check whether treatment is working or a flare is starting.
What is a normal faecal calprotectin level?
There is no single normal level. Results are given in micrograms per gram of stool, and each laboratory sets its own cut-off. NICE notes that 50 micrograms per gram is the cut-off most test makers use (NICE). Some NHS laboratories use a higher cut-off of 100 for adults, with a grey zone above it.
Two NHS laboratories, for example, use these bands for adults:
- North Bristol NHS Trust: under 100 is low risk; 100 to 250 is a grey zone, so the test is repeated; over 250 is high risk.
- University Hospitals Sussex: under 100 points to IBS or another cause; 100 to 200 is repeated in 6 weeks; over 200 leads to an urgent specialist referral.
Always read your result against the range printed on your own report. Normal ranges can also vary with age (Cleveland Clinic).
What does a high result mean?
A high result means there is inflammation in the bowel. In the North Bristol data, about 46 in 100 adults with a level over 250 had IBD (North Bristol NHS Trust). So a high result raises the chance of IBD, but it is not a diagnosis on its own.
What does a borderline result mean?
A result in the grey zone is often repeated after 4 to 6 weeks. Your doctor may ask you to stop anti-inflammatory painkillers and stomach acid medicines first, if it is safe to do so (North Bristol NHS Trust).
What else can raise calprotectin?
IBD is not the only cause. According to MedlinePlus, calprotectin can also be raised by:
- Bacterial gut infections and food poisoning
- Coeliac disease
- Bowel cancer
- Anti-inflammatory painkillers (NSAIDs), such as ibuprofen, aspirin and naproxen
- Stomach acid medicines (PPIs), such as omeprazole
A normal result can still miss some cases, mostly in children (MedlinePlus). That is why your doctor looks at the result together with your symptoms.
How is the stool sample collected?
You collect a small sample at home and it goes to the laboratory. You do not need to fast. MedlinePlus gives these general steps:
- Label the container with your name and the date and time.
- Catch the stool on clean paper or plastic wrap over the toilet, or in a clean, dry container.
- Keep it free of urine, toilet water and toilet paper.
- Put a small amount in the container, close it tightly and wash your hands.
- Return it as soon as you can. Cleveland Clinic advises getting the sample to the laboratory quickly.
Tell your doctor about any medicines you take, but do not stop a medicine unless your doctor tells you to.
What happens after your result?
- Low or normal: inflammation is unlikely. Your doctor may treat you for IBS or look for another cause. A colonoscopy is usually not needed (MedlinePlus).
- Borderline: the test is usually repeated in a few weeks.
- High: your doctor will usually refer you to a gastroenterologist, who may arrange a colonoscopy to find the cause.
When should you see a doctor?
See a doctor if bowel symptoms last more than a few weeks, or if you notice blood in your stool, black stools, weight loss you cannot explain, or diarrhoea that wakes you at night. Call 998 for an ambulance if you have severe belly pain, are vomiting blood or feel faint.
In Dubai, a Medilife doctor can see you at home for AED 250 and decide which tests you need. See doctor at home. If you have been asked to do a calprotectin test, a Medilife nurse can collect the sample at your home or hotel. See calprotectin test at home in Dubai.
Frequently asked questions
Is faecal calprotectin a blood test?
No. It is measured in a stool sample, not in blood.
Can children have a calprotectin test?
Yes. NICE recommends it for children with suspected IBD who have been referred to a specialist. A normal result is a little less reliable in children.
Can calprotectin diagnose Crohn’s disease or ulcerative colitis?
No. It shows inflammation, not the cause. A specialist confirms IBD, usually after a colonoscopy.
Should I stop ibuprofen before the test?
Ask your doctor. NSAIDs such as ibuprofen can raise the result, but do not stop any medicine without advice.
How long does a calprotectin result take?
It depends on the laboratory. Some NHS laboratories quote about a week (University Hospitals Sussex).
Need the test in Dubai? Call or WhatsApp Medilife on +971 52 345 2647 to arrange home sample collection.
Medically reviewed by Dr Marina Girgis, General Practitioner, DHA licence 71970809-004, on 7 November 2026.