Gastroenteritis typically lasts only one or two days, but in some cases, it may last for a week, WebMD advises. Gastroenteritis is the medical term for an upset stomach and is sometimes called "stomach flu," although this term is inaccurate.
Gastroenteritis includes symptoms of nausea and vomiting and sometimes diarrhea and fever, WebMD explains. Gastroenteritis is commonly caused by a virus, and the two main types are rotavirus and norovirus. Gastroenteritis is typically spread by coming into contact with someone who has the virus, by failing to wash hands after using the bathroom or touching a dirty diaper, or by eating or drinking contaminated food or water.