Calprotectin (Stool)
A stool test that measures calprotectin levels to detect intestinal inflammation and help distinguish inflammatory bowel disease from irritable bowel syndrome.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
What this test measures
Calprotectin is a protein released by neutrophils (a type of white blood cell) when they are activated in response to inflammation in the intestinal lining. When the gut becomes inflamed, the immune system sends neutrophils to the affected area, and these cells release calprotectin into the intestinal space, where it mixes with stool. Measuring calprotectin in a stool sample therefore provides a direct, noninvasive indicator of whether intestinal inflammation is present.
The test's primary clinical application is distinguishing between inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, and irritable bowel syndrome (IBS). Both conditions are chronic and produce overlapping symptoms including diarrhea, abdominal cramping, and pain, but only IBD involves active inflammation. This distinction matters because IBD requires anti-inflammatory or immunosuppressive treatment to prevent progressive intestinal damage, while IBS is managed differently. Calprotectin testing can help healthcare providers determine whether the symptoms warrant invasive diagnostic procedures like colonoscopy or whether a noninflammatory cause is more likely.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Individuals experiencing chronic digestive symptoms such as persistent diarrhea, abdominal pain, cramping, or bloating that have lasted several weeks or come and go over time.
- Patients with symptoms that could indicate either inflammatory bowel disease or irritable bowel syndrome, particularly when other diagnostic tests have not provided clear answers.
- Those who have noticed blood in their stool or have experienced unexplained weight loss along with digestive symptoms.
- Individuals with a family history of inflammatory bowel disease who are experiencing gastrointestinal symptoms and want to assess their risk.
- Patients already diagnosed with IBD who need to monitor disease activity or assess response to treatment without undergoing invasive procedures.
- Those who prefer a non-invasive screening test before considering more invasive diagnostic procedures like colonoscopy or endoscopy.
What to expect
Preparation
No special preparation is needed for this test. No fasting is required, and individuals can eat normally before providing the sample.
Sample Type
The test requires a small stool sample, typically just a teaspoon-sized amount or less. The sample is collected at home using a clean container provided by the laboratory.
Collection
Individuals will receive a sterile container and instructions for proper collection. The sample should not be contaminated with urine or water, and the outside of the container should remain clean.
Turnaround
Results are typically available within 2-3 business days after the laboratory receives the sample.
Understanding your results
Results are reported as a numerical value in micrograms per gram of stool (μg/g). Normal calprotectin levels (typically below 50 to 100 μg/g, depending on the laboratory) suggest that significant intestinal inflammation is unlikely, making IBD less probable as the cause of symptoms. Moderately elevated levels may warrant monitoring and possible repeat testing, as transient elevations can occur with infections or medication use. Markedly elevated levels strongly suggest active intestinal inflammation and typically prompt further evaluation, which may include colonoscopy or imaging. Healthcare providers interpret calprotectin alongside symptom severity, duration, stool patterns, and other clinical findings to guide the diagnostic approach.
| Population | Reference Range | Notes |
|---|---|---|
| Adults | <50 μg/g | Normal range suggesting no significant intestinal inflammation |
| Adults | 50-120 μg/g | Borderline elevated; may indicate mild inflammation or require repeat testing |
| Adults | >120 μg/g | Elevated; suggests active inflammatory process in the gastrointestinal system |
Reference ranges may vary by laboratory and individual factors. Results should be interpreted by a healthcare provider in the context of your overall health.
What does a “Low” result mean?
Normal or low calprotectin levels typically suggest that the intestines are not inflamed, which means inflammatory bowel disease is less likely. Low levels indicate little to no inflammation in the intestines, so symptoms are likely caused by a non-inflammatory bowel condition such as irritable bowel syndrome. Calprotectin concentrations below 50 μg/g are not suggestive of an active inflammatory process, and further evaluation for functional gastrointestinal disorders may be considered.
What does a “High” result mean?
Elevated calprotectin levels typically indicate inflammation in the intestines, with higher levels corresponding to more inflammation. High levels may suggest conditions such as ulcerative colitis, Crohn's disease, colorectal cancer, or infection. Calprotectin concentrations above 120 μg/g are suggestive of an active inflammatory process and may be observed in various conditions including inflammatory bowel disease, celiac disease, colorectal cancer, and gastrointestinal infections. Additional testing may be recommended to determine the specific cause of the inflammation.
Privacy & confidentiality
Test results are confidential and protected under HIPAA regulations. Your results will not be shared with your personal doctor unless you request it, will not be added to your medical records without your consent, and will not appear on insurance explanation of benefits statements.
Frequently asked questions
Related tests
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Another inflammatory marker that may be elevated in patients with IBD or other inflammatory conditions
View TestCeliac Disease Panel
Important to rule out celiac disease, which can also cause intestinal inflammation and similar symptoms
View TestRelated conditions
Last reviewed: April 2026
CPT Code: 83993
This test may not be available in: NY, NJ, RI
This page is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider regarding any health concerns. LevelPanel does not diagnose, treat, or prescribe.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
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