Inflammatory Bowel Disease

Abstract

Crohn disease (CD) and ulcerative colitis (UC) were often considered one disease until Charles Wells first differentiated the two in 1952. This review outlines the disease features and symptoms of CD and UC. Indeterminate colitis is described, as are the epidemiology, diagnostic testing, and etiology of inflammatory bowel disease (IBD). The role of genetics in the development of IBD is discussed as well as innate immunity, the adaptive immune system, and cytokine signaling. Drugs used in the medical management of IBD and the future of surgical treatment for IBD are described. Tables detail histologic features and symptoms of CD and UC; genetic and demographic risk factors for IBD; common IBD-associated genes, including those associated with epithelial barrier dysfunction, innate immunity, antigen presentation, T cell differentiation, cytokine production, and cell signaling; the medical treatment of IBD; 5-aminosalicylate derivatives and sites of action; advantages of genetic markers in predicting disease course; surgical application of personalized medicine; and surgically relevant IBD genes. Figures show the timeline of IBD, gross CD pathologic specimens, gross UC colectomy specimens, histologic slides of CD- and UC-affected colonic tissue, genetic and environmental factors contributing to IBD, genes involved in innate and adaptive immunity of CD, three components of the gene key to bacterial recognition, typical course of CD, treatment for a hospitalized UC patient, top-down versus bottom-up treatment of IBD, and the Kono-S procedure. This review contains 12 figures, 10 tables, and 242 references.