Questions: Do you mean why would anybody place the OP on the board or why would anybody put somebody else's shit up their ass?
Answers: The OP was placed because it was thought to be interesting in a disease treatment context. It's also fun to say "turd bank". If all your intestinal flora was destroyed by the antibiotics that kill off clostridium difficile, which would ultimately kill you off if it weren't controlled, you would need some new flora from somewhere before the lack of flora killed you.
Did you actually read the article?