In Recurrent Clostridium Difficile Colitis, What Treatment Next?

Many treatments have failed but evidence is accumulating in support of a newcomer. Do you know which one it is?

A patient has had multiple recurrences of Clostridium difficile colitis and has been treated with several courses of metronidazole and vancomycin. As soon as the antibiotics are discontinued, however, symptoms recur.

 

Which of the following treatments should be recommended next?