Why is Ed obsessed with certain bodily functions?

Rev. Schnell:
Yes indeed, Ed surely was traumatized during the time he was being potty trained. Now he is totally obsessed with pooping and peeing, how wonderful is that? Yes, Ed is an extraordinary artist. Ed is fortunate to have ROX, a place where he can act out his obsessions, and a topic we all have a daily interest in. Maybe Ed could engage in a deeper discussion of these bodily functions. How about the joys of pooping and peeing? Looking forward to this discussion.