Sucks to be sick. Not the flu, as GI issues are pretty rare for flu for your age group. I know it doesn't make it any easier to deal with. Could be food poisoning, or any number of really crappy rota/noro virus infections that spread this time of year, especially to those with kids. As you probably have some antibodies to it already from your own childhood, it isn't unusual to get a very short, but somewhat intense, illness from this stuff this time of year. Mojo.