Inflammatory bowel disease inflammatory 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 rectum. Microscopically, ulcerative colitis is restricted to the mucosa (epithelial lining of the gut), while Crohn's disease affects the full thickness of the bowel wall ("transmural lesions"). Lastly, Crohn's disease and ulcerative colitis present with extra-intestinal manifestations (such as liver problems, arthritis, skin manifestations and eye problems) in different proportions. In 10–15% of cases, a definitive diagnosis neither of Crohn's disease
Stephen Crohn Stephen Crohn Stephen Lyon Crohn (September 5, 1946 – August 23, 2013) also known as "The man who can't catch AIDS", was a man notable for a genetic mutation, which caused him to be immune to AIDS. He was a great-nephew of Burrill Bernard Crohn, for whom Crohn's disease is named. Crohn had the "delta 32" mutation on the CCR5 receptor, a protein on the surface of white blood cells that is involved in the immune system and serves as an access route for many forms of HIV virus to enter and infect host cells. This mutation rendered him effectively