It's variable. I think it can take several days, although it's usually quicker than that. Maybe you should call your mother and check.

I haven't exactly been keeping track, but I have the vague feeling that a lot of people I know have been getting "stomach flu" lately. I've been wondering if it might be that swine flu.

I've never been sure whether influenza involves the digestive tract or not. That thing we called "Asian Flu" when I was a kid was all about throwing up. But for years and years I've been reading articles in the popular press insisting that there is no such thing as "stomach flu," that real influenza is a respiratory disease, that so-called "stomach flu" is always food poisoning, etc. etc. But early reports of the swine flu in Mexico mentioned - guess what - vomiting. Hmmm.

Anyway, it's been making me a little nervous each time an LJ friend reports being felled by this... thing. So I'm relieved to hear you are both recovering. Sorry you got sick.