Table 3. Comparison between Crohn's disease and ulcerative colitis.

	Crohn's disease	Ulcerative colitis
Age of onset	Bimodal 15-30 years, 60-70	Bimodal, 15-30, above 60
Common sites	Terminal ileum (could be from mouth to anus)	Colon and rectum
Gross features	Focal aphthous ulcer with intervening normal mucosa, linear fissures, cobblestone appearance	Crypt abscesses
Microscopic	Non-caseating granuloma	Limited to mucosa and submucosa
Colorectal cancer risk	1-3%	5-25%
Symptoms	Crampy abdominal pain, diarrhea	Bloody diarrhea
Complications	Fistula, abscesses stricture, obstruction	Toxic megacolon
Surgery role	Treatment of complications	Curative