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
Burrill Bernard Crohn help his father, Theodore, who suffered from severe indigestion. Crohn married Lucile Pels in 1912, and had two children, Edward Crohn (1917-2013), a physician, and Ruth Crohn Dickler (1914-2016) a New York City resident, known for her philanthropy. They divorced in 1927. He later married Rose Blumenthal in 1948. In addition to practicing medicine, Crohn enjoyed painting and studying history of the American Civil War. Crohn's watercolors were frequently displayed in galleries in New Milford, Connecticut. Crohn practiced medicine until he was 90, splitting time in his later years between the Upper East Side of Manhattan and a country home