I scored a nice juicer off craigslist a couple of years ago. I had read the Klein book and decided what the heck, I'd give it a try. So I did a juice diet for maybe 3 or 4 days, then very slowly added some cooked veggies, and went pretty slow for a couple of weeks. As it is, I was already pretty thin, and I lost about
10 pounds doing this (and it was the first time people commented that I looked ill), BUT at the same time, my bleeding stopped. My poo didn't come out liquid, but was greatly diminished, soft, once or twice a day.
As I added more foods, I added meat, fats (coconut oil - yum!), raw fruits and veggies, and several months later some "grains" like sweet potato.
So after this experience, if I had to do it again, I probably would, but somehow have to figure out a way not to loose so much weight so fast. That was kinda scary.
The other thing to note was that drinking only fresh juice for several days, my energy level was very very low, so you'd want to do it when you didn't have much else going on in your life.