Oh really, who cares? They're both books about poo. The aesthetic choice (if one can have an aesthetic choice about such subject matter) is clearly "What's Your Poo." It's infinitely cuter and doesn't try to trick me into believing in some wacko religion.
I guess my real question is "Why is all this publishing energy going into poop related books?" Am I going to have to write a book-length poem on bowel movements in order to get published? Wait a minute. . . that's not such a bad idea. Where's the Ex-Lax?
Buy Poo here.