2238. Calprotectin (stool)

Calprotectin is a protein synthesized by neutrophils, monocytes, and epithelial cells. Elevated levels of this protein in feces indicate inflammation of the intestinal mucosa, making this test a sensitive, noninvasive marker for differentiating between inflammatory (organic) and functional (e.g., irritable bowel syndrome) bowel diseases.

This test is best performed in conjunction with a stool analysis and a fecal occult blood test.

Calprotectin is a neutrophil cytolytic protein with antimicrobial properties, the concentration of which increases in feces in cases of epithelial damage and immune response activation. Decreased calprotectin levels may indicate the absence of active inflammation, and follow-up measurements allow for the evaluation of therapy effectiveness.

Determining the amount of calprotectin in a patient's feces, in conjunction with clinical manifestations, is used to diagnose inflammatory bowel diseases, particularly in cases of suspected:

• ulcerative colitis;
• Crohn's disease;
• infectious colitis;
• non-cancerous bowel diseases accompanied by inflammation.

This test helps avoid unnecessary colonoscopy if calprotectin levels are low.

When?

• If inflammatory bowel disease (IBD) is suspected: recurrent abdominal pain, diarrhea, blood, or mucus in the stool.
• Before referral for colonoscopy – as an initial screening test.
• To monitor IBD activity during treatment and remission.
• For repeated episodes of diarrhea alternating with constipation, abdominal discomfort – to differentiate functional disorders (IBS) from inflammatory conditions.

Who should consider it?

• Patients with suspected Crohn's disease or ulcerative colitis.
• Children and adolescents with chronic complaints of abdominal pain and changes in bowel habits.
• Individuals for whom colonoscopy is contraindicated or for whom it is necessary to determine the appropriateness of one.
• For patients after treatment of IBD to monitor remission or early detection of exacerbation.

• Stool