Communicating Risk and Safety of Inflammatory Bowel Disease Therapies

Inflammatory bowel diseases (IBD) often require long-term treatment with advanced therapies, including biologics and small molecules. The use of these agents must be carefully balanced against the risks of uncontrolled gastrointestinal inflammation and the potential for treatment-related adverse events. This review synthesizes contemporary evidence on malignancy, infection, venous thromboembolism (VTE), and major adverse cardiovascular events (MACE) in IBD, integrating risks attributable to underlying disease and those conferred by specific drug classes, with the goal of improving how clinicians communicate these risks to patients. Chronic intestinal inflammation increases the risk of colorectal cancer, small bowel adenocarcinoma, intestinal lymphoma, anal cancer in fistulizing Crohn's disease, and cholangiocarcinoma in those with primary sclerosing cholangitis, alongside modest excesses in select extraintestinal malignancies. Thiopurines increase the risk for lymphoma, particularly when combined with anti-TNF agents, and non-melanoma skin cancer. Corticosteroid use is the major driver of serious infection, VTE, and MACE, while combination anti-TNF-thiopurine therapy, JAK inhibitors, and S1P receptor modulators are associated with therapy- and context-specific infectious and thrombotic risks, which remain low in absolute terms for most patients. Across outcomes, we emphasize absolute risk and patient-level modifiers, and provide pictorial tools that depict clinically meaningful risks to support shared decision-making and individualized, evidence-based risk communication with patients.