In my case it is more a case of juice going straight through me. I've found that if I break my fast with juice as opposed to whole fruits the juice can just pass straight through. As I said there is little discomfort, apart from having to stay near a loo and having to run occasionally but I've definitely found whole fruits are better. It's one reason why I'd never do a juice fast also, though I never really liked that idea anyway. Luckily for me I read about dry fasting before anything else and that I've always found to be the best for me.