Ileitis, backwash

Ulcerative colitis is confined to the rectum and colon, and affects the mucosa and the submucosa. In some instances, a short segment of terminal ileum may be inflamed this is referred to as backwash ileitis. Unlike Crohn s disease, the deeper longitudinal muscular layers, serosa, and regional lymph nodes are not usually involved. Fistulas, perforation, or obstruction are uncommon because inflammation is usually confined to the mucosa and submucosa. 

Ulcerative colitis is an inflammatory bowel disease limited to the mucosa and submucosa of the colon. The disease typically begins in the rectum and continuously extends proximally to involve part of the colon or the entire colon (pancolitis). In 10-40% of cases, the distal ileum is also inflamed, which is referred to as backwash ileitis. The most severe... 

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