The invention provides active and passive immunization methods for preventing and treating Clostridium difficile infection, which involve percutaneous administration of C. difficile toxin-neutralizing polyclonal immune globulin, C. difficile toxoids, or combinations thereof. Also provided by the invention are C. difficile toxoids, C. difficile toxin-neutralizing polyclonal immune globulin, and methods of identifying subjects that produce C. difficile toxin-neutralizing polyclonal immune globulin.