CRP and inflammatory bowel disease: SFB-positive patients exhibited significantly higher disease activity indices (PCDAI, <i>P</i> = 0.005; PUCAI, <i>P</i> = 0.021) and elevated inflammatory markers (fecal calprotectin, <i>P</i> = 0.001; C-reactive protein, <i>P</i> = 0.001; erythrocyte sedimentation rate, <i>P</i> = 0.001) compare with SFB-negative patients.<h4>Conclusions</h4>SFB positivity occurred more frequently in pediatric IBD than in controls-especially in active disease-and was associated with higher inflammatory activity and disease severity.