Here is a good post (see link below) on P and B shakes, but I would add to it that some people need a laxative herb product on the same days as taking Pand B shakes, otherwise they wouldn't even be able to take one shake without loosing all bowel movement completely (if they even had any before beginning the P and B program). Packaged sets are available of both a laxative herb mix and a psyllium mix, some with the B "bentonite" added and some not. OR you can buy each separately. What has worked for me:
The product "para-gone" also spelled "Paragone", has anti- parasite herbs (a good thing) and has Cape Aloe, which is a laxative herb, then on the same days I take P and B shakes.