Your faecal calprotectin result
Short patient information to print or keep.
What it measures
Calprotectin is a stool marker of bowel inflammation. It is not a diagnosis of Crohn’s disease, ulcerative colitis or cancer. I interpret the result with your symptoms, medicines and other investigations.
Check the value, units and laboratory comments
Laboratories use different methods and reference ranges. A result flagged as high does not by itself mean you need a colonoscopy. I check the value, units, laboratory comments and your symptoms. The units µg/g and mg/kg have the same numerical value.
A high result has several possible causes
IBD, infection, diverticular inflammation and some medicines can raise calprotectin. Tell your clinician about recent illness, travel and medicines. Do not stop prescribed treatment or change IBD medicines yourself to alter the number.
A repeat may help
A modest rise may settle; persistent or substantial elevation may need further assessment. For people with established IBD, symptoms and inflammation do not always change together: ongoing symptoms may have another cause, while mild symptoms do not guarantee quiet inflammation. Serial faecal calprotectin tests can help monitor the trend alongside clinical review.
A low result has limits
It does not rule out bowel cancer, all small-bowel Crohn's disease or every cause of diarrhoea. Calprotectin can be elevated in some people with colon cancer, but it is not a bowel cancer screening test. FIT measures blood, calprotectin measures inflammation, and infection tests look for germs. None replaces the others. Microscopic colitis may also occur with a normal result.
Agree follow-up
Follow the laboratory collection and return instructions. Our team will explain how you will receive a result I arrange. Please get in touch if it is overdue. Persistent bleeding, weight loss, iron deficiency or worsening diarrhoea needs review regardless of the number. Severe symptoms need urgent assessment.
Do not wait for a stool result if you are getting worse
Persistent rectal bleeding, unexplained weight loss, iron deficiency or diarrhoea that continues or worsens needs clinical review, even with a low result. Severe pain, significant bleeding, repeated vomiting, fever with marked illness or dehydration need urgent assessment.
Call 111 if you collapse or are too unwell to travel safely. Do not wait for a routine appointment or an email reply.
General information. Follow your own care instructions.