E. coli (0157:H7) colitis has a predilection for involvement of the transverse colon and both ascending/descending colon with right sided predominance. The location of bowel involvement may give clues to the type of infectious colitides. 

Typhoid fever (salmonellosis) has a predilection for involving the cecum, ascending colon and invariably in ileum. Shigellosis  predominantly affect the descending colon. Campylobacteriosis affect the small bowel and colon. 

Clinical history will often provide clue to the underlying etiology. Non-infectious cause of colitis to be considered  include  inflammatory bowel disease in adults, ischemic colitis in the elderly and pseudomembraneous colitis.