Poor you, I had a nasty bug like that almost 2 years ago when ds was 8 months, I just kept drinking lots of fluids and dumping ds in the cot every time I had to run to the loo! It lasted 6 weeks for me despite tests at the Drs who recommended I keep eating and drinking and breastfeeding ds as much as possible. The only thing which finally seemed to work was eating at least 3 of those activia yoghurts with their good bacteria on a daily basis (wish I had tried that earlier!).
Another thing for stomach upsets which is ok for breastfeeding is Viridian capsules which I think you can get from Holland and Barrett, my mum sent them to me and I take them now if I get a dodgy tummy (yes, still breastfeeding and he's 2.6 - still waiting for self weaning to happen!!!)
I've had this bug for a few days now and am barely eating. I feel really dehydrated and concerned that its impacted my milk supply. My dd is v wingy and just seems to want to be latched on all the time (presumably because she isn't getting much milk at the mo). Any tips on how to cope? I'm really struggling. She will not drink formula and solid intake is patchy!