I can't remember but for some reason I thought you said you had been dehydrated.
Have you tried anything like this:

"Trioral Oral Rehydration Salts
Good for dehydration cramps
The World Health Organization (WHO) has a recommended recipe for oral rehydration salts. This concoction has saved many millions from dying of cholera – you dissolve a particular mix of salts and sugar in water, and it keeps you from dehydrating to death long enough for your immune system to kick the bacteria. I use the salts for less dramatic issues – I often get dehydration cramps in the wee hours after extended travel, while hiking in the Florida Summer sun – those sorts of things. This fixes me right up. I’ve used these for years."
From Cool tools website
http://kk.org/cooltools/