If you have diarrhea or stomach flu, do you have colitis? or, is colitis diagnosed only if your bowel symptoms never clear up?

Colitis: There are many types of colitis, inflammation of the lining of the colon. Infectious colitis can come from bacteria in bad food or bad water and resolve with treatment. Crohn's colitis and ulcerative colitis need to be diagnosed with testing such as colonoscopy. Ischemic colitis comes from low blood flow. Viral conditions such as the "flu" are not likely to cause colitis that i know of.

You can have colitis: Colitis is a non specific term that means inflammation of the colon. It has many causes. Infection is one cause and viruses can cause that. The term ulcerative colitis refers to a specific type of inflammatory bowel disease. Colitis can cause diarrhea and rectal bleeding along with pain. Typically uc symptoms cause intermittent flare-up of symptoms.