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Faecal Calprotectin

Checked: 23-08-2019 by 3 Vicky Ryan Next Review: 23-08-2021


COVID-19 Update (8.6.20) - Please note that Faecal Calprotectin tests are now being accepted again.

The local pathway for Faecal calprotectin below has been developed with local gastroenterologists, BNSSG CCG  and the West of England Academic Health Science Network  (WEAHSN).

Faecal calprotectin (FC) can be a useful test for helping to distinguish between Inflammatory bowel disease and Irritable bowel syndrome in adult patients aged 18 to 60. The similarity in symptoms of these two conditions can lead to delay in reaching an accurate  diagnosis for those suffering from IBD, and can subject those with IBS to unnecessary and invasive procedures such as colonoscopy.

Before undertaking the test please note the following:

  • This is not a test for colorectal cancer and should not be used in patients where this diagnosis is being considered. See Lower GI - USC (2WW) page.
  • Certain medications, such as PPIs and NSAIDs can alter the result making it difficult to interpret
  • Infective gastroenteritis may cause transient elevation of FC. Consider stool culture in patients with suspected infective symptoms. Following an infection it may take between 2-6 weeks for FC to normalise and this should be considered prior to referral.
  • It should be emphasised that this test is designed to support clinical decision making rather than to replace it. If clinicians have a strong suspicion that a patient has organic pathology in the bowel despite a normal FC, then they should back their clinical judgement and refer as appropriate.


Please also consider the following pages on Remedy for further advice:

Inflammatory Bowel Disease

Irritable Bowel Syndrome


FIT test

Faecal Calprotectin in children

Local paediatric gastroenterologists have advised that Faecal Calprotectin is not usually a useful test for children with abdominal pain. It should only be used if a clinical history is suggestive of possible IBD and in conjunction with other blood investigations (see the Chronic abdominal pain in children page). If IBD is suspected then a referral should be made to paediatric gastroenterology and FC can be sent while awaiting their opinion.

Interpretation of results

Interpretation of results

Using this pathway will categorise patients into one of three groups - those at high, low or intermediate risk of having IBD.

High Risk if FC >250 mcg/g 

If the test result is above 250mcg/g, the patient falls into the high risk group as there is a 46% chance they have IBD. An urgent referral to gastroenterology should be considered via eRS (or direct access colonoscopy if that is patient choice and considered clinically appropriate).

If acute severe colitis is suspected then patient should be discussed with on call gastroenterology team as admission may be appropriate.

Low Risk  if FC <100 mcg/g

If the result is less than 100 mcg/g then risk of IBD is very small (<2%) then alternative diagnoses such as Irritable Bowel Syndrome should be considered. Invasive investigations such as colonoscopy are not normally recommended at this stage unless there is still strong clinical suspicion of bowel pathology.

Intermediate Risk  if FC between 100 and 250 mcg/g

If the FC result is between 100 and 250 and there are no symptoms of acute severe colitis then ensure NSAIDs and PPIs have been withheld for at least 4-6 weeks and then repeat test.

  • If the repeat result then falls below 100mcg/g then the risk of IBD is very low and no further investigations would normally be indicated
  • If the repeat result remains between 100 and 250 the risk of IBD is approximately 12% and referral for direct access colonoscopy should be considered to confirm the diagnosis.
  • If the repeat result is >250mcg/g then treat as high risk as above.

Red Flag

This is not a test for colorectal cancer and should not be used in patients where this diagnosis is being considered. See Lower GI - USC (2WW) page.

If IBD excluded

If IBD has been excluded but FC remains elevated then alternative causes of elevated calprotectin should be considered and investigated as appropriate. Conditions that may need to be excluded include:

  • Coeliac disease - check TTG antibodies
  • Diverticulitis - manage appropriately if identified at colonoscopy.
  • Dental infections - advise patient to see their General dental practitioner.
  • Gut infections - consider stool M,C and S to exclude infections such as giardia or campylobacter which can cause prolonged symptoms.
  • Chest infections - FC  may be elevated due to swallowed infected sputum.
  • Upper or small bowel pathology - investigation should be directed according to other GI symptoms such as dyspepsia/reflux, weight loss or abnormal blood tests such as anaemia.

If above conditions have been excluded or treated but FC still raised then consider gastroenterology referral via eRS or advice and guidance. (also available via eRS)


A video on the Faecal Calprotectin pathway has been produced by West of England AHSN featuring Charlie Andrews, a GP and Regional Clinical Champion for IBD for the RCGP. The video can be viewed on the following link:

Further information can be found in the NICE guidelines - Faecal calprotectin diagnostic tests for inflammatory diseases of the bowel

Efforts are made to ensure the accuracy and agreement of these guidelines, including any content uploaded, referred to or linked to from the system. However, BNSSG ICB cannot guarantee this. This guidance does not override the individual responsibility of healthcare professionals to make decisions appropriate to the circumstances of the individual patient, in consultation with the patient and/or guardian or carer, in accordance with the mental capacity act, and informed by the summary of product characteristics of any drugs they are considering. Practitioners are required to perform their duties in accordance with the law and their regulators and nothing in this guidance should be interpreted in a way that would be inconsistent with compliance with those duties.

Information provided through Remedy is continually updated so please be aware any printed copies may quickly become out of date.