Clostridioides difficile Infection in Special Populations: Focus on Inflammatory Bowel Disease-A Narrative Review from Pathogenesis to Management.

Clostridioides difficile infection (CDI) is a major complication in inflammatory bowel disease (IBD), due to coexistence of altered microbiota, chronic inflammation, and immune dysregulation. This narrative review summarizes recent evidence on the epidemiology, pathogenesis, risk factors, diagnosis, and management of CDI in IBD. Overall, IBD patients have a four- to five-fold higher risk of CDI than the general population and face more severe courses, higher rates of hospitalization, colectomy, recurrence, and mortality. Pathogenesis involves profound dysbiosis with loss of butyrate-producing Firmicutes and Bacteroidetes, bile acid imbalance that promotes spore germination, and enhanced toxin effects on an already inflamed mucosa. Major risk factors include active colonic disease, broad-spectrum antibiotic exposure, prolonged hospitalization, and corticosteroid or combined immunosuppressive therapy. Diagnosis requires careful integration of stool assays with clinical evaluation, supported by endoscopy or imaging when needed, to distinguish infection from IBD flares. Recommended first-line treatments are fidaxomicin or oral vancomycin, reserving fecal microbiota transplantation for recurrent or high-risk cases. Optimal IBD control is essential to reduce both primary and recurrent infection. CDI and IBD share a mutual pathogenic interplay in which microbial, immune, and therapeutic factors from each condition drive and magnify the other. Early recognition, guideline-based antibiotic therapy, judicious use of immunosuppression, and microbiota-based preventive strategies are crucial to improve patient outcomes and limit recurrence, thus reducing healthcare costs.