I don't recommend things like Pau D'arco except at the beginning of the process, before diet changes have been implemented etc. You can take it with Primal Defense, but it will kill some of the friendlies. Better to take PD With Primal Defense than to take it alone. If you're consistently taking Primal Defense then you probably don't need Pau D'arco.
I got reactions from it when I moved up to 2 pills a day - a rash on my thigh that quickly went away. Guess those yeasties were a'fightin' back and lost! woo hoo!
As long as you take the psyllium and Primal Defense apart from each other it's fine. I'd recommend doing psyllium 2-3 times a day, build up to it tho. Gots to keep that colon moving and cleansing, especially when you're detoxing with a fast etc.