Fecal calprotectin test

Fecal calprotectin is a protein that is produced by neutrophils. It is released into the stool when there is inflammation in the intestines.

Fecal calprotectin levels can be measured in a stool test to help diagnose and monitor inflammatory bowel disease (IBD) and other conditions that cause intestinal inflammation.

How is fecal calprotectin tested?

Fecal calprotectin is typically tested using an enzyme-linked immunosorbent assay (ELISA) in a stool sample . The results are reported as a concentration in micrograms per milligram of stool (μg/mg).

sample collection procedure:

No special preparation required

collect the fresh random stool specimen. No preservative should be added to the sample container.

Stool samples cannot be collected from diaper.

Do not add previously collected sample.

Normal fecal calprotectin levels

The normal range for fecal calprotectin varies depending on the laboratory that performs the test. However, most laboratories consider levels below 50 μg/mg to be normal. Levels above 50 μg/mg are considered to be elevated and may indicate inflammation in the intestines.

Normal- </= 50 μg/gm

Borderline – 50.1-120μg/gm

Abnormal ->/=120 μg/gm

Interpreting fecal calprotectin results

Increased levels seen in

celiac disease

crohn’s disease

infectious colitis

ulcerative colitis

Necrotising enterocolitis


Fecal calprotectin results should be interpreted in the context of the patient’s clinical presentation. For example, a patient with diarrhea and abdominal pain who has an elevated fecal calprotectin level is likely to have IBD or another condition that causes intestinal inflammation. However, a patient with elevated fecal calprotectin levels and no symptoms of intestinal inflammation may have a different underlying condition, such as celiac disease or Crohn’s disease.

what is calprotectin?

calprotectin is a major soluble protein in cytosol of neutrophils. It is released extracellularly during neutrophil activation or during cell death and also following endothelial adhesion of monocytes. As a result it can be detected and quantified in fluids where inflammation is occurring for example serum, urine, cerebrospinal fluid and feces. Calprotectin resist proteolysis in the gut lumen and remain remarkably stable within feces at room temperature for at least 7 days.

Elevated fecal calprotectin indicates the migration of neutrophils to intestinal mucosa during inflammation . This test is helpful ancillary diagnostic test for inflammatory bowel disease and is biomarker for treatment assessment.

The level of calprotectin in stool correlates significantly with endoscopic colonic inflammation in both ulcerative colitis and crohn’s disease. Calprotectin shows a higher sensitivity and specificity than lactoferrin.

Clinical applications of fecal calprotectin

Fecal calprotectin can be used for a variety of clinical applications, including:

  • Diagnosis of IBD 
  • Monitoring disease activity in IBD: Fecal calprotectin can be used to monitor disease activity in patients with IBD. For example, a decrease in fecal calprotectin levels after starting treatment for IBD suggests that the treatment is effective.
  • Differentiating between IBD and irritable bowel syndrome (IBS): Fecal calprotectin can be used to help differentiate between IBD and IBS, which have similar symptoms. For example, patients with IBD typically have higher fecal calprotectin levels than patients with IBS.

Interference : Aspirin, and Nonsteroidal anti inflammatory (NSAIDs) medications can increase fecal calprotectin levels.


Although calprotectin is a screening test for IBD it cannot fully replace conventional endoscopy and radiology. fecal calprotectin measurement is a practical, safe and non-invasive method of quantifying intestinal inflammation


Mosby’s diagnostic and laboratory test reference, 16th edition.

Yamamoto T. The clinical value of faecal calprotectin and lactoferrin measurement in postoperative Crohn’s disease. United European Gastroenterol J. 2015 Feb;3(1):5-10. doi: 10.1177/2050640614558106. PMID: 25653853; PMCID: PMC4315679.

Lamb CA, Mansfield JC. Measurement of faecal calprotectin and lactoferrin in inflammatory bowel disease. Frontline Gastroenterol. 2011 Jan;2(1):13-18. doi: 10.1136/fg.2010.001362. Epub 2010 Nov 3. PMID: 23904968; PMCID: PMC3724198

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