The only critical thing about juice is adding the correct amount with the oil. Also, don't drink so much later in the day that you become nauseated. Drink water too, stay hydrated. Good luck with your flush, I hope everything goes smoothly and you'll feel great.

I am on the small side too. My first flush, I drank all the juice. I have done 11 flushes since and only drink the juice occasionally- maybe on 2 other flushes. I did the malic acid twice. I don't find any difference, personally, between when I drink the juice, use malic acid, or skip all of it. Also, I did a 30 day juice fast and then flushed- horrible idea. I had no bile to flush everything out. It was my least productive flush and made me feel the sickest. I did some research later, and they say not to flush after a fast like that for this very reason.

Are you able to provide the details of the flush you are doing? I am a first timer also, excited to do it but still nervous and want to make sure I do the right flush.