My questions too! I was taking Pysllium for a long time, and heard the same thing. I also wanted to try primal defense, and they recommend not taking any herbal colon cleansers or pyslium while on it because it interfers with the ability of the probiotics to colonize.
So, I'm trying it out...whatever I find I'll post. I've also started on bioxy cleanse, which I think is similar to other Oxypowder s. It gets thing moving. I'm also taking Fiberific, which is a soluable fiber and seems to help. So far I've not missed the pysllium.