Immune checkpoint inhibitor-related gastrointestinal adverse events: a disproportionality analysis based on the FAERS database

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment but are frequently linked to gastrointestinal immune-related adverse events, which can severely affect patient outcomes. We conducted a retrospective pharmacovigilance study using the FDA Adverse Event Reporting System (2011–2024). Disproportionality analyses (ROR, PRR, BCPNN, MGPS) identified gastrointestinal adverse events (AEs) associated with ICIs across pan-cancer populations, while multivariable logistic regression and Bayesian network modeling were used to examine influencing factors. A total of 85 distinct gastrointestinal toxicities were identified and categorized as ICI-related gastrointestinal AEs (GI AEs). Substantial variation in ICI-related GI AE profiles was observed across different ICI regimens, with anti-CTLA-4 demonstrating the highest toxicity (ROR = 17.76 [16.88–18.68]). Logistic regression and Bayesian network analyses indicated that disease stage, concurrent targeted therapies, and ICI type significantly influenced the risk of developing ICI-related GI AEs. Patients with gastric variceal hemorrhage exhibited the highest mortality rate (63.64%). Our pharmacovigilance analysis reveals a high risk of gastrointestinal adverse events with ICI therapy, especially anti-CTLA-4. Stage IV disease, concurrent targeted therapies, and anti-CTLA-4 therapy or combination therapy further increase this risk, highlighting the need for personalized treatment strategies.