Diagnostic Utility of Fecal Calprotectin in Inflammatory Bowel Disease: A Cross-Sectional Study from Bangladesh

Abstract

Background: Fecal calprotectin (FC), a neutrophil-derived protein, serves as a valuable non-invasive biomarker for assessing intestinal inflammation. While extensively proven useful in Western cohorts, its clinical use in South Asian populations and specifically Bangladeshis, has not been fully explored.

Methods: This cross-sectional study included 90 patients: 23 diagnosed with Crohn’s disease (CD), 22 with ulcerative colitis (UC), and 45 with irritable bowel syndrome (IBS), who served as a control group. Laboratory parameters analyzed comprised hemoglobin (Hb), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and fecal calprotectin. An FC amount greater than 200 µg/g was considered above normal. Statistical analyses included the Wilcoxon rank sum test, Spearman’s correlation, receiver operating characteristic (ROC) curve analysis, and chi-square tests to assess group differences and associations.

Results: Patients with IBD exhibited markedly higher median FC levels (UC: 459 µg/g; CD: 404 µg/g) than those with IBS (35 µg/g). None of the studies reported significantly different FC, CRP or ESR results between UC and CD subgroups. FC showed a strong positive correlation with CRP (ρ = 0.704) and a strong inverse correlation with Hb (ρ = –0.687), highlighting its alignment with systemic inflammation and anemia. Elevated FC (>200 µg/g) was significantly associated with increased CRP, ESR, and low Hb levels (all p < 0.001). ROC analysis demonstrated excellent diagnostic performance for identifying CRP-positive individuals (AUC ≈ 0.90).

Conclusion: Fecal calprotectin demonstrates robust diagnostic utility for differentiating IBD from IBS in Bangladeshi patients. Since it correlates well with usual inflammatory markers, it can support clinical monitoring when endoscopy is not possible.