This is a randomized controlled trial to compare the effect of a 10-day course of per oral
metronidazole versus a one-time rectal instillation of an anaerobically cultivated human
intestinal microbiota for the treatment of a first occurrence of Clostridium difficile
infection (CDI). Recurrent CDI is common after standard antibiotic treatment. We hypothesize
that the instillation of a healthy intestinal microbiota will be more effective in inducing a
durable cure than metronidazole for primary CDI.