Bugger I hate it when you can have something for a while then your stomach decides not any more. The coconut water has lots of naturally occurring electrolytes and minerals for hydration so could be worth a try for you. You can get it in Woolies and Coles.

Lots of people can't stomach water, some swear by Coke, but it didn't work for me. If it is something you can drink you need to try to sneak some water in with it or the sugar will dehydrate you, catch 22