Can calprotectin distinguish Crohn's disease from ulcerative colitis?

No. Calprotectin indicates the presence and rough magnitude of intestinal inflammation but does not distinguish between causes. Endoscopy, histology, and imaging are required to differentiate IBD subtypes and exclude infection or other inflammatory conditions.

Is fasting or dietary restriction required before collecting a stool sample?

No. There is no fasting or dietary preparation for faecal calprotectin. Patients should avoid collection during menses or if the specimen is contaminated with urine, and ideally defer testing until at least two weeks after acute gastroenteritis resolves.

Why should the test be delayed after acute gastroenteritis?

Enteric infections transiently elevate calprotectin, which can mimic or obscure IBD. Testing too soon after acute illness increases the risk of a false-positive result; waiting two weeks or more allows transient infection-related inflammation to resolve.

Do NSAIDs affect the result?

Yes. NSAIDs cause enteropathy and raise faecal calprotectin even in the absence of IBD. A drug history — including over-the-counter ibuprofen, naproxen, and aspirin — is essential to interpretation, and stopping NSAIDs before testing may be considered if clinically appropriate.

What does a calprotectin level between 50 and 200 µg/g mean?

Values in this equivocal range may reflect low-grade inflammation, recent infection, medication effect, or assay variation. Clinical context and often repeat testing guide the decision to proceed with endoscopy or to observe and retest.

Can a normal calprotectin rule out inflammatory bowel disease?

A low calprotectin (<50 µg/g) has high negative predictive value and makes active IBD highly unlikely in an adult with chronic symptoms and no alarm features. It does not exclude quiescent IBD, proximal small-bowel disease, or non-inflammatory causes of symptoms.

How is calprotectin used to monitor IBD in remission?

Serial calprotectin measurements track mucosal healing and predict relapse. Rising levels during clinical remission often precede symptomatic flare, allowing practitioners to intensify therapy pre-emptively. Persistently normal values are reassuring and may support de-escalation or extended dosing intervals in selected patients.

BML-MBG-009microbiome gutUSA

Calprotectin Stool Add-On

Q: What is the difference between faecal calprotectin and faecal lactoferrin?

Both are neutrophil-derived proteins that mark intestinal inflammation, but calprotectin has been more extensively validated, has better-established clinical thresholds, and is more widely used in IBD guidelines. Lactoferrin may be substituted when calprotectin assays are unavailable.

Q: How is calprotectin used to monitor IBD in remission?

Serial calprotectin measurements track mucosal healing and predict relapse. Rising levels during clinical remission often precede symptomatic flare, allowing practitioners to intensify therapy pre-emptively. Persistently normal values are reassuring and may support de-escalation or extended dosing intervals in selected patients.

Q: Are reference ranges different in children?

Yes. Infants and young children have physiologically higher calprotectin, with levels declining toward adult thresholds by age four. Age-specific reference intervals must be applied in paediatric interpretation to avoid false-positive results.

The Calprotectin Stool Add-On quantifies a neutrophil-derived protein in stool to detect and monitor intestinal inflammation. It distinguishes inflammatory bowel disease from functional disorders, stratifies endoscopy risk, tracks mucosal healing, and predicts relapse in established IBD, offering a non-invasive bridge between symptoms and endoscopic assessment.

Biomarkers

Stool

Sample

5–7 business days

Turnaround

Fasting

What is the Faecal Calprotectin test?

The Calprotectin Stool Add-On quantifies a neutrophil-derived protein in a stool specimen to detect and gauge intestinal inflammation. Practitioners order it to differentiate organic inflammatory disease from functional gastrointestinal disorders, to stratify patients for endoscopy, and to monitor disease activity and response to therapy in established inflammatory bowel disease without repeated invasive procedures. Faecal calprotectin has transformed the diagnostic pathway: a low value in an adult with chronic diarrhoea or abdominal pain makes active IBD unlikely and can spare unnecessary colonoscopy, while an elevated concentration prompts timely endoscopic and histological assessment. Serial measurements track mucosal healing, predict relapse, and help clinicians titrate immunosuppression or biologics. Because calprotectin is stable ex vivo and requires only a small stool sample, it bridges the gap between clinical symptoms — which correlate poorly with endoscopic inflammation — and invasive assessment.

What does the Faecal Calprotectin test measure?

FC(Faecal Calprotectin)

Range: <50 µg/g in adults; method- and age-dependent thresholds apply.Optimal: Thresholds vary by guideline; many adopt <50 µg/g as normal, 50–200 µg/g as equivocal, and >200 µg/g as consistent with active inflammation warranting endoscopic assessment.µg/g / mg/kg

Calprotectin is a calcium- and zinc-binding heterodimer of S100A8/A9 subunits, abundant in the cytoplasm of neutrophils, monocytes, and reactive macrophages. When innate immune cells infiltrate the intestinal mucosa and lumen in response to inflammation, calprotectin is released and remains stable in stool for several days at room temperature, making it a convenient surrogate for intestinal neutrophil flux. Its faecal concentration correlates with the extent and severity of mucosal inflammation but does not distinguish aetiology.

Faecal calprotectin is the most widely validated non-invasive biomarker for detecting and monitoring intestinal inflammation. It distinguishes inflammatory bowel disease from functional disorders with high sensitivity and negative predictive value, guides decisions about endoscopy, and tracks mucosal healing during therapy. Elevations occur in any condition that draws neutrophils into the gut lumen — active IBD, enteric infection, NSAID enteropathy, colorectal neoplasia, and diverticulitis — so clinical context determines the next step.

Why is the Faecal Calprotectin test ordered?

Evaluation of adults or children with chronic diarrhoea, abdominal pain, or blood in stool to distinguish inflammatory bowel disease from irritable bowel syndrome or other functional disorders
Risk stratification before endoscopy in patients with suspected IBD, where a low calprotectin may defer or obviate colonoscopy
Monitoring of disease activity and mucosal healing in patients with established Crohn's disease or ulcerative colitis on maintenance therapy
Assessment of relapse risk in patients with IBD in clinical remission, where rising calprotectin often precedes symptomatic flare
Post-operative surveillance in Crohn's disease to detect early endoscopic recurrence without routine ileocolonoscopy
Investigation of suspected enteric infection, NSAID enteropathy, or microscopic colitis when clinical presentation and stool microbiology do not fully explain symptoms
Follow-up of colorectal polyp surveillance or unexplained iron-deficiency anaemia when luminal inflammation is in the differential

Sample collection and turnaround

Sample type

Stool

Fasting required

Collection method

At-home collection kit

Turnaround

5–7 business days

Collection notes

Patient collects a small stool sample using the kit supplied by Doctor's Data and ships it to the laboratory according to the kit instructions. No dietary preparation is required. Avoid collection during menses or if obvious blood or urine contaminates the specimen. Ideally defer testing until at least two weeks after resolution of acute gastroenteritis and note current NSAID or PPI use on the requisition.

Specimen requirements

Approximately 5 g of stool (roughly the size of a walnut) in the collection vial provided. Calprotectin is stable at room temperature for several days, so ambient shipping is acceptable; refrigeration extends stability. Doctor's Data provides detailed collection and shipping instructions with the kit.

What can affect Faecal Calprotectin results?

elevatesNon-steroidal anti-inflammatory drugs

NSAIDs cause enteropathy and increase intestinal permeability, raising faecal calprotectin even without overt IBD; a drug history is essential to interpretation.

elevatesEnteric infection and gastroenteritis

Bacterial, viral, and parasitic infections recruit neutrophils to the mucosa and lumen, transiently raising calprotectin; test during or shortly after acute illness can yield false-positive results for IBD.

elevatesProton-pump inhibitors

Long-term PPI use is associated with modest elevations in some studies, possibly through alterations in microbiome or low-grade colonic inflammation; the magnitude is typically less than seen in active IBD.

elevatesAge — infancy and early childhood

Physiological calprotectin levels are substantially higher in the first year of life, declining toward adult thresholds by age four; age-specific reference intervals must be applied in paediatric interpretation.

variableWatery or liquid stool

Dilution by liquid stool can lower the concentration measured per gram; some laboratories recommend caution interpreting results from very watery samples or correlating with stool consistency.

variableDelay in specimen processing or improper storage

Calprotectin is stable at room temperature for several days and refrigerated for weeks, but prolonged delay or freeze-thaw cycles may degrade the protein; specimen-handling instructions must be followed.

What do Faecal Calprotectin results mean?

Elevated

Values >200 µg/g are consistent with active intestinal inflammation — inflammatory bowel disease, enteric infection, NSAID enteropathy, diverticulitis, or colorectal neoplasia. Endoscopy and stool microbiology, guided by history, localise and define the cause. Modest elevations (50–200 µg/g) may reflect low-grade inflammation, recent infection, or medication effect and often warrant repeat testing or clinical correlation before proceeding to invasive investigation.

Normal

A normal result argues against significant mucosal inflammation at the time of collection and, in the appropriate clinical context, can defer or avoid endoscopy. In patients with established IBD, normal calprotectin during remission is reassuring and associated with lower relapse risk, though it does not guarantee histological healing.

Reduced

Faecal calprotectin <50 µg/g in an adult makes active inflammatory bowel disease highly unlikely (high negative predictive value) and supports a functional diagnosis when symptoms are chronic and alarm features are absent. It does not exclude quiescent IBD, non-inflammatory causes of symptoms, or small-bowel pathology beyond the reach of neutrophil shedding.

Note: Calprotectin is sensitive for inflammation but not specific for IBD — any process that recruits neutrophils to the gut can raise it. NSAIDs, acute infection, PPIs, and paediatric age affect interpretation. Assay platforms and cutoffs differ between laboratories, so serial monitoring should use the same method. A single elevated value in a well patient may not warrant endoscopy; clinical context, repeat testing, and a full gastrointestinal history guide the decision.

Frequently asked questions

Both are neutrophil-derived proteins that mark intestinal inflammation, but calprotectin has been more extensively validated, has better-established clinical thresholds, and is more widely used in IBD guidelines. Lactoferrin may be substituted when calprotectin assays are unavailable.

How to access the Faecal Calprotectin test

The Faecal Calprotectin reference page is free and open to all practitioners. Create a free practitioner account to see pricing, save tests to your list, and generate requisition forms. Verification takes 1–2 business days.

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About this page

Published: October 7, 2026

Last reviewed: October 7, 2026

References:

Feagan BG, et al. ECCO–ESGAR guideline for diagnostic assessment in IBD Part 1: initial diagnosis, monitoring of known IBD, detection of complications. J Crohns Colitis. (2019)
Lamb CA, et al. British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults. Gut. (2019)
Mosli MH, et al. Systematic review and meta-analysis: fecal calprotectin for assessment of inflammatory bowel disease activity. Inflamm Bowel Dis. (2015)
Panes J, et al. Systematic review: the use of ultrasonography, computed tomography and magnetic resonance imaging for the diagnosis, assessment of activity and abdominal complications of Crohn's disease. Aliment Pharmacol Ther. (2011)
D'Haens G, et al. Fecal calprotectin is a surrogate marker for endoscopic lesions in inflammatory bowel disease. Inflamm Bowel Dis. (2012)

This content is for licensed healthcare practitioners only and does not constitute medical advice. Clinical decisions should be based on the full clinical picture and not on any single test result.