Gastroenteritis is a general term referring to inflammation or infection of the gastrointestinal tract, primarily the stomach and intestines. It can be caused by infection with bacteria, viruses, or other parasites, or less commonly reactions to new foods or medications. Many times it involves stomach pain (sometimes to the point of crippling), diarrhea and/or vomiting, with noninflammatory infection of the upper small bowel, or inflammatory infections of the colon.
It usually is of acute onset, normally lasting fewer than 10 days and self-limiting. Sometimes it is referred to simply as 'gastro'. It is often called the stomach flu or gastric flu even though it is not related to influenza.
