[CORed]

"Stomach flu" is not really the flu. True flu, which flu shots protect against, is primarily a respiratory disease, like a really nasty cold, but with fever, aches, and usually feeling too crappy to get out of bed, and often a lingering cough for a few weeks after the worst is over. It usually comes on very suddenly.

"Stomach flu" is caused by things like rotavirus, Norwalk virus, or sometimes is actually bacterial food-borne infection or food poisonint: salmonella, staph food poisining, etc. Unfortunately, flu shots won't keep you from getting stomach flu. Good hygeine, frequent hand washing, etc, and careful food preparation, will reduce your risk of "stomach flu" somewhat, but is no guarantee that you won't get it. "Stomach flu" sucks, but fortunately, it usually doesn't last mor than a few days.