Abstract

Crohn’s disease and ulcerative colitis, collectivelyreferred to as inflammatory bowel diseases (IBD), are chronic idiopathic inflammatory diseases of the gastrointestinal tract. IBD is generally regarded as a “Western” world disease, and its frequencyhas increased considerablyover the past few decades. ¹ Quality of life is severely affected in IBD patients, mainly due to chronic relapses of disease. Complications such as stenoses and strictures are frequent in Crohn’s disease, leading to multiple resections of affected parts of the gastrointestinal tract. In addition, chronic ulcerative colitis is associated with an increased frequency of colonic adenocarcinoma. Although the exact pathogenesis of IBD is still mostly unknown, enormous progress has been made in recent years to obtain a better understanding. This chapter will summarize the current status of our understanding of the pathogenesis of IBD.