I have read that one should only take one shake at first, and then if you have bowel movements (two at least) the next day, only then is it ok to increase the number of shakes, etc. Starting off with three and noticing that you are not having movements each day, it would be best to back off to taking only one, and trying that for awhile to see how it goes.
Some people end up not able to use psyllium unless they use laxative herbs on the same days, otherwise the psyllium product just clogs things up for them.
That combination, psyllium product and laxative herbs, can work well for some of those people.
This is all just based on the millions of curezone posts I've read (well not millions, but you know what I mean) :-) good luck