Can I ONLY add water to GoLYTELY�?

I have a colonoscopy coming up in the 2nd week of April. I have been given a gallon container with "GoLYTELY�" in it. The directions say to add water to it, & drink 8 oz. of it every 30 to 40 minutes. Do you think I could add apple juice to it INSTEAD of water? It would make it more tolerable. Apple juice IS one of the liquids I can drink prior to the exam. If you DO recommend I add water, do you have any tips on getting through it?