This article reviews a selection of 50 papers on inflammatory bowel disease published between April 2000 and June 2001. The new information summarized here includes: the discovery of the association of the NOD2 gene with Crohn's disease; the role of bacteria and the modulating effects of probiotics; the inverse association of appendectomy and ulcerative colitis; progress in imaging based on magnetic resonance imaging and leukocyte scintigraphy; assessment of the value of anti-Saccharomyces cerevisiae antibodies in the screening of inflammatory bowel disease and differentiation between ulcerative colitis and Crohn's disease; and risk factors and management of dysplasia and cancer. This article does not review all therapeutic aspects, but focuses on smoking cessation; anti-tumor necrosis factor antibody treatments; the usefulness of measuring erythrocyte 6-thioguanine metabolite levels to optimize purine analogue therapy; strictureplasty; and the long-term results of ileoanal anastomosis.