I have no idea what the protocol is, but I would offer food, milk and water. I've only had to deal with one sickness bug, when ds2 was 2, and he wouldn't touch food, but he would take the odd sip of water. That's not much help is it? Sorry.
All these poorly babies
I hope they're better soon. It's horrible for them and bloody hard work to parent.
I'm off out to watch Edgar J tonight, I might have to warn my friend to give me a nudge if I drop off 
I am now the branch coordinator of my local branch of the NCT There's so much to do. It's kind of scary, but also a challenge.