If all that isn't coming out... something must be keeping it in!
I would highly recommend suspending the B&P. In fact, I think it is somewhat counterproductive to the way a fast works, i.e., removing the task of digestion from the body in order to allow cleansing, detoxing and healing to take place. I like to do my b&p with a cleansing/rebuilding diet post fast.
Meanwhile, consider an enema to help move things along. Be sure to drink more water than you think earthly possible!