My notes explain why P&B will make you seem constipated at first. It's like asking an invalid to bench press 300 pounds. They're nto going to be able to do that at firs,t will they? But would you say don't bench press ever again? No, you'd just lower the pounds and give them whatever spotting help they need.
Same with adding fiber to your diet. It's doing lots of good things like pushing mucus and dead garbage through the 6 feet of the colon, and that can slow it down. Plus you probably aren't having the peristaltic action that you should at first, due to weak colon. These two things alone will make you constipated, but you just deal - keep cleansing, do what you can to make sure you ahve at least one BM a day, and after a month to three months, you see things that make your eyes pop.