- Patients with two episodes of Clostridium dificile infection defined as having resolved symptoms after an initial microbiologically confirmed diagnosis of C. difficile, who have completed a course of antibiotics, and have a second positive test (toxin or PCR) obtained for a relapse of diarrhea symptoms by treating providers. Subjects with a positive "test of cure" stool sample (NOT advised by SHEA guidelines) in the absence of relapsed symptoms of CDI, or those who never improved their symptoms on the initial course of antibiotics will not be eligible. (Subjects who do not have a response to antibiotics may have other or additional diagnoses which are not likely to be helped by FMT.)