i have the same problem, but instead of P&B shakes i've been taking only Psyllium. i started releasing ropes around the same time i started taking Psyllium, which was approximately 3 weeks ago. at first i was elated because i thought they were actual mucoid plague, but after a while, it got old fast. i was constipated often and i needed enemas almost everyday, and low and behold every enema i had some mucoid in it. at first i thought that maybe mucoid passing through my colon caused this constipation, whether it's true or not i'm still not sure. but my advice for you since we're on the same boat is try to eat other foods high in fiber and see what you release. if you don't release anything after ingesting a good 50 grams of natural fiber from fruits and veggies daily, then we will all know the real culprit. it's good that you brought this up, because i was wondering the same thing and i never thought otherwise until you mentioned it. i'm going off the psyllium today and i'll let you know my results.