Sugar Shakers - need help with some questions

I am still trying to loose 35 lbs. Have been a WW. but I am a sugar person and my gastroentologist advised me to give SB a try. So I am trying to do that.
Just read the book. My question is about constipation and so on.
I drink a 1/3 cp prune juice each morning that seems to do it for me but the sugar is so high.
I am at a loss at what to do. I do have diver ticulosis.
I guess I am afraid of not drinking this juice. I know this topic is a bit gross but I am desparate to loosing the rest of this weight.
Thankyou everyone.
Hilde

Well because of the high fiber of the whole wheat and the veggies you should not have any problems. Are prunes on the SB book's no no list?
Usually fruit sugars are ok as long as fruit is the only ingredient. I lent my book you or I'd look.
If you have any problems how about Metamucil?