Interleukin-1beta (IL-1beta) is a pivotal mediator in the inflammatory immune response that is characteristic of a number of chronic disorders. The etiology and pathophysiology of inflammatory bowel disease (IBD) have for many years been an enigma. The recent identification of the inflammasome, a multiprotein complex responsible for interleukin-1beta converting enzyme (ICE, caspase-1) activation, has generated new possibilities for the elucidation of the etiology and pathophysiology of IBD and as a consequence also for the identification of new treatment targets.