I switched to Gatorade2 low fat less sugar & I only drink grape flavor which is very good for your digestive system
After years of relying on Gatorade, I started getting nausea and gastric discomfort with it. I then moved on to a generic Pedialyte. Months later the same issue came up, so now I rotate different brands (seems to help). I too assumed it was the sugar.
I'm assuming you drink Gatorade for the sodium, so here is everything I have tried.
I started taking salt tablets (CMC are 1 gram NaCl, which is close to 400 mg of sodium) instead of relying entirely on electrolyte drinks. I had to buy these from Amazon.
Fludrocortisone/Florinef helps a lot for me. Some people resort to V8, but I can't stand the flavor. I just eat high-sodium (or "non-'healthy choice'" soups as often as I tolerate.