<unk>  <unk>  is a group of<unk>  conditions of the large intestine and, in some cases, the small intestine.
The main forms of<unk>  are Crohn's<unk>  and ulcerative colitis (UC).
Accounting for far fewer cases are other forms of<unk> :
Collagenous colitis
Lymphocytic colitis
Ischaemic colitis
Diversion colitis
Behçet's syndrome
Infective colitis
Indeterminate colitis
The main difference between Crohn's<unk>  and UC is the location and nature of the<unk>  changes. Crohn's can affect any part of the gastrointestinal tract, from mouth to anus (skip lesions), although a majority of the cases start in the terminal ileum. Ulcerative colitis, in contrast, is restricted to the colon and the anus. 
Microscopically, ulcerative colitis is restricted to the mucosa (epithelial lining of the gut), while Crohn's<unk>  affects the whole<unk>  wall.
Finally, Crohn's<unk>  and ulcerative colitis present with extra-intestinal manifestations (such as liver problems, arthritis, skin manifestations and eye problems) in different proportions.
In rare cases, patients have been diagnosed with both Crohn's<unk>  and ulcerative colitis, which is really called Crohn's colitis.
Inflammatory bowel disease
Crohn's disease
Irritable bowel syndrome
Allergic colitis
Ulcerative colitis
Drug-induced colitis
Chemical colitis
Microscopic colitis