Abstract Background Fecal immunochemical test (FIT), widely used in colorectal cancer screening, has emerged as a potential biomarker of endoscopic activity in inflammatory bowel disease (IBD). Compared to fecal calprotectin, FIT offers greater standardization, automation and availability, with simpler handling and potentially better adherence. Its implementation could potentially streamline non-invasive monitoring, but its diagnostic accuracy in IBD remains unclear. We therefore conducted a systematic review and meta-analysis to evaluate its performance. Methods Selection of studies: assessing the accuracy of FIT to estimate endoscopic activity in IBD patients. Search strategy: electronic bibliographical searches up to October 2025. Data synthesis: meta-analyses of the FIT were performed combining the sensitivity (Se), specificity (Sp), likelihood ratios (LRs), and diagnostic odds ratio (DOR) of the individual studies. Heterogeneity among the studies was assessed by the I-squared (I2)] statistic. Results Eighteen studies (Table 1) met the inclusion criteria: 12 focused on ulcerative colitis (UC), 2 on Crohn’s disease (CD), and 4 on both UC and CD. Twelve studies employed the standard cut-off for FIT provided by the manufacturer or used the same cut-off as for colorectal cancer screening (usually considered the common threshold), while 6 studies estimated their optimal cut-off values. When we considered all studies (including 1,881 patients and 2,206 assessments), the accuracy of FIT for the diagnosis of endoscopic activity was (pooled values): Se: 0.7, Sp: 0.88, LR+: 5.56, LR-: 0.34, and DOR: 16.39 respectively. Significant heterogeneity was observed across the studies (I2 62%). Most of the available studies were based exclusively on patients with UC (including 1,554 patients and 1,904 assessments), so we performed a subgroup analysis including only this type of IBD, finding a pooled Se, Sp, LR+, LR- and DOR of 0.76, 0.86, 5.89, 0.28 and 20.97 respectively. On the other hand, in patients with CD (327 patients, 302 assessments), the corresponding values were 0.53, 0.86, 3.75, 0.55 and 6.79. Conclusion FIT demonstrates moderate-to-high diagnostic accuracy for detecting endoscopic activity in IBD, particularly in UC. Therefore, FIT may represent a promising non-invasive tool for assessing IBD disease activity. However, significant heterogeneity among studies underscores the need for further research to optimize cut-off values and define the role of FIT in routine IBD monitoring. Conflict of interest: Gonzalez, Victor: None Chaparro, María: Grant: Pfizer, Takeda, Janssen, Galápagos, Biogen, Abbvie Personal Fees: Gilead, Pfizer, Faes, Tillots pharma, Lilly Gisbert, Javier: Grant: MSD, Abbvie, Pfizer, Kern Pharma, Biogen, Mylan, Takeda, Janssen, Roche, Sandoz, Celgene/Bristol Myers, Gilead/Galapagos/Alfasigma, Lilly, Sanofi, STADA, Teva, Ferring, Faes Farma, Shire Pharmaceuticals, Dr. Falk Pharma, Tillotts Pharma, Chiesi, Casen Fleet, Gebro Pharma, Otsuka Pharmaceutical, Norgine, Italfarmaco, and Vifor Pharma. Personal Fees: MSD, Abbvie, Pfizer, Kern Pharma, Biogen, Mylan, Takeda, Janssen, Roche, Sandoz, Celgene/Bristol Myers, Gilead/Galapagos/Alfasigma, Lilly, Sanofi, STADA, Teva, Ferring, Faes Farma, Shire Pharmaceuticals, Dr. Falk Pharma, Tillotts Pharma, Chiesi, Casen Fleet, Gebro Pharma, Otsuka Pharmaceutical, Norgine, Italfarmaco, and Vifor Pharma. Other: MSD, Abbvie, Pfizer, Kern Pharma, Biogen, Mylan, Takeda, Janssen, Roche, Sandoz, Celgene/Bristol Myers, Gilead/Galapagos/Alfasigma, Lilly, Sanofi, STADA, Teva, Ferring, Faes Farma, Shire Pharmaceuticals, Dr. Falk Pharma, Tillotts Pharma, Chiesi, Casen Fleet, Gebro Pharma, Otsuka Pharmaceutical, Norgine, Italfarmaco, and Vifor Pharma.
González et al. (Thu,) studied this question.