What an idea - Gatorade are the sponsers and their sports drink have:
Water, sucrose, dextrose, citric acid, electrolytes (sodium chloride, sodium citrate, potassium phosphate, magnesium carbonate), flavourings, antioxidant (ascorbic acid), modified starch, emulsifiers (gum arabic, sucrose acetate isobutyrate), colour (beta-carotene)
Should be ok.. I might also organise a well placed supporter to throw me a bottle of tap water mid run and then we're away!
I'm doing a marathon next year so may need to invest in a bottle belt for that. All bottled water and coke are out - not sure how I would cope in an IM. Ugh.