Photo Credit: Lars Neumann

The following is a summary of “Fecal calprotectin from ileostomy output in patients with Crohn’s disease,” published in the February 2025 issue of the BMC Gastroenterology by Park et al.

Fecal calprotectin (FC) is a well-established biomarker for assessing disease activity and postoperative recurrence in patients with Crohn’s disease (CD). However, its utility in individuals with an ileostomy remains inadequately understood. This study aimed to determine whether FC levels derived from ileostomy output could reliably predict postoperative small bowel inflammation in patients with CD. A retrospective analysis was conducted on data from patients with CD and an ileostomy who underwent FC testing between January 1, 2015, and December 30, 2022. Participants were included if they had FC measurements performed concurrently with imaging and/or endoscopic evaluations, enabling a direct comparison between FC results and objective assessments of small bowel inflammation. 

FC levels were assessed using both a point-of-care (POC) test, referred to as FC-POCT, and an enzyme-linked immunosorbent assay (ELISA), referred to as FC-ELISA. A total of 101 patients and 224 FC test results were analyzed. FC concentrations were significantly higher in patients with active small bowel inflammation, as confirmed by imaging or ileostomy, compared to those in remission. Specifically, FC-POCT levels in patients with active inflammation had a median of 191.0 µg/g ([IQR], 94.6–499.0 µg/g), while those in remission had a significantly lower median of 29.9 µg/g (IQR, 29.9–50.0 µg/g; P < 0.001). Similarly, FC-ELISA levels were markedly elevated in patients with active inflammation (median 252.5 µg/g; IQR, 118.5–911.0 µg/g) compared to those in remission (median 16.8 µg/g; IQR, 8.2–33.0 µg/g; P < 0.001). The optimal cutoff values for distinguishing between inflammation and remission were 63.3 µg/g for FC-POCT ([AUC], 0.90; 95% [CI], 0.88–0.97) and 40.1 µg/g for FC-ELISA (AUC, 0.89; 95% CI, 0.79–0.99), indicating high diagnostic accuracy. 

Moreover, a comparative analysis of the two testing methods revealed no statistically significant difference in diagnostic performance (P = 0.692), suggesting that both approaches are equally effective in detecting inflammation. These findings highlight the potential of FC measurement from ileostomy output as a noninvasive, highly sensitive, and specific biomarker for monitoring postoperative small bowel inflammation in patients with CD. The ability to reliably detect inflammation through FC testing could enhance clinical decision-making, allowing for timely intervention and personalized treatment strategies in postoperative CD management. Further prospective studies are warranted to validate these results and establish standardized FC thresholds for routine clinical use in this patient population.

Source: bmcgastroenterol.biomedcentral.com/articles/10.1186/s12876-025-03652-1