[What is inflammatory bowel disease?].

Inflammatory bowel diseases are chronic conditions of unknown origin that result from continuous or intermittent inflammation of a part of the intestinal wall. The main classic types of IBD are ulcerative colitis, Crohn's disease and indeterminate colitis that cannot be classified accurately as ulcerative colitis or Crohn's disease with pure colonic involvement. The two main subtypes of microscopic colitis, namely lymphocytic and collagenous colitis, fulfill the criteria that define IBD and should be considered as true IBD.