ABSTRACT
A role for the gut bacterial flora in the etiology of chronic inflammatory bowel disease (IBD) has been thought likely since the early isolation of etiological agents from patients with acute colitis. In the early stages the symptoms of acute and chronic IBD are shared and only when the disease has been established for some time can a diagnosis of chronic IBD be considered. The study of the role of bacteria in the causation of IBD is complicated by the fact that chronic IBD is not a single entity but has three major and a host of minor forms. The major forms are Crohn's disease (CD), ulcerative colitis (UC), and irritable bowel syndrome (IBS). UC is an inflammatory disease of the mucosal layer of the large intestine and, although it usually affects the distal colon and rectum, it may involve the whole of the large bowel.
