Optimal Treatment for Recurrent Clostridium Difficile

Inclusion Criteria:

   - Informed consent obtained and signed

   - Age > 18

   - If female, participant must not be pregnant or nursing

      - Negative pregnancy test required for females <61 years of age or without prior
      hysterectomy

   - Confirmed current diagnosis of CDI, determined by having

      - >3 loose or semi-formed stools for participants over 24 hours AND

      - Positive stool assay for C. difficile

      - EIA positive for toxin A/B; or

      - Cytotoxin assay; or

      - Nucleic Acid Amplification Test (NAAT, PCR or LAMP) based detection of toxigenic
      C. difficile

   - Current episode represents the first recurrent episode of CDI within 3 months of the
   primary CDI episode in a patient who has not had CDI in the 3 months prior to the
   primary episode OR a second recurrent CDI episode occurring within 3 months of the
   first recurrent episode, as defined above

      - At least one of the previous CDI episodes must have been confirmed by a stool
      assay for C. difficile

Exclusion Criteria:

   - Inability to provide informed consent

   - Inability to take oral capsules

   - Receipt of >72 hours of antibiotics considered effective in the treatment of CDI,
   including:

      - metronidazole

      - vancomycin

      - fidaxomicin

      - nitazoxanide

      - rifaximin

   - Prior infusion of bezlotoxumab within the previous 6 months

   - Known presence of fulminant CDI, including hypotension, severe ileus or GI obstruction
   or incipient toxic megacolon

   - Receipt of more than a single course of oral vancomycin, fidaxomicin, or a vancomycin
   tapering regimen since the primary episode of CDI as defined above

   - Known allergy to vancomycin or fidaxomicin

   - Acute or chronic diarrhea due to inflammatory bowel disease or other cause (e.g.,
   presence of an ileostomy or colostomy) that would confound evaluation of response to
   CDI treatment

   - Anticipation of need for long term systemic antibiotic treatment (beyond 7 days)

   - Patients with an active diagnosis of COVID-19 will be excluded from the study, but
   patients who have recovered (per current CDC guidance on discontinuation of
   transmission-based precautions) can be included in the study.