This diet is so gross. Even when you decide to blend instead of juice so you can drink the fiber, you still end up with uncontrollable runs. If you want to do this diet, please find a way to avoid society and people altogether until you are done with your fast.
http://www.youtube.com/watch?v=Zi_XLOBDo_Y RIP MJ from San Diego
Sorry that this was your experience, but I think perhaps (please correct me if I'm wrong) that you terminated the reboot too early. The first few days of a juice fast are indeed hard to get through. The body is detoxing from whatever poisons that are inside the person (the older and heavier they are, the more bad stuff needs to come out) and this is a painful process. One of the side effects of detoxing is diarrhea, as you seem to have discovered.
The good news is that eventually the detoxing stage is over and the digestive system is able to recover and you are able to reap the benefits of juicing.