If you're worried about throwing up or feeling nauseous, I have found it really is best to do some sort of fast beforehand. You might want to try the supereasy Apple Fast before your liver flush. Whole organic apples, cut into 4...eat one whenever you're hungry. Drink lots and lots of warm water in between apples. (buy a variety!) The 3Day apple fast is a great detoxifier....detoxes all your cells! You'll be ready for that liver flush.
If you want to find out more about it check out the Edgar Cayce Forum.