C.J.
While personally never had the pleasure, I have heard from many friends and co workers (parents of girls and boys) who have dealt with the poop smear issue. One gal's daughter would do it when she woke up from her nap! After two times of complete nursery room disenfecting, she was quicker on the monitor - LOL.
While totally gross, it is normal. Is he potty training? It could also be that he is exploring what is typically going into the potty? Just a thought. Kids are pretty inquisitive.
So sorry for you having to clean this up. . .