Fecal Calprotectin as a Diagnostic Marker for Inflammatory Bowel Disease:
A Prospective Cohort Study

Abstract

This study evaluated fecal calprotectin as a non-invasive biomarker for
distinguishing inflammatory bowel disease (IBD) from irritable bowel
syndrome (IBS) in patients presenting with chronic gastrointestinal symptoms.

Results

Sensitivity of 93% was observed in distinguishing IBD from IBS using fecal
calprotectin measurements. The negative predictive value was 96%, making it
highly effective for ruling out IBD in symptomatic patients.

Fecal calprotectin levels above 250 µg/g strongly correlate with endoscopically
confirmed active intestinal inflammation. Patients with levels below 50 µg/g
had a less than 1% probability of having significant intestinal inflammation.

The receiver operating characteristic (ROC) analysis demonstrated an area
under the curve (AUC) of 0.95 for distinguishing IBD from functional
gastrointestinal disorders.

Clinical Implications

Calprotectin is recommended as a first-line non-invasive test before
colonoscopy. Implementing calprotectin screening reduced unnecessary
colonoscopies by 67% in our cohort while maintaining diagnostic accuracy.

The biomarker showed consistent performance across age groups, with no
significant variation in sensitivity between pediatric and adult populations.
