Advances in the drug treatment of inflammatory bowel disease include the development of site-specific delivery systems for 5-aminosalicylate (5-ASA), topically active corticosteroids with minimal systemic bioavailability, and a variety of antagonists to specific inflammatory mediators. These novel therapeutic approaches have emerged from pharmaceutical improvements on traditional drugs and also from an improved understanding of the mucosal immune system and the pathogenesis of inflammatory bowel disease.