I just recently(yesterday) passed some MP in less than a week of doing P&B. I have not been fasting whatsoever but I did do at least 2, sometimes 3 shakes a day, except for the first day. I usually did the shakes first thing in the morning, once during the day and then one at night about an hour before bedtime.
I was having a little cramping, which I took as a good sign according to what I've read here but I wasn't having luck in pushing much of anything out. During the evening, I did a dump and went to wipe, and found that it was not all the way out (sorry if too much info), being clumped together. It was very dark but really skinny long clumps in weird shapes. So later in the night, feeling encouraged, I did a warm water enema
and that is when an extensive amount vacated. This was much lighter in color and looser in consistency. It looked almost like a telephone coil, except it was much thicker in some parts and attached by thinner parts. I don't know if that makes much sense. ANyway, I think this was a success and I will keep going.