Inclusion Criteria:

• 1. Provision of signed and dated informed consent form
• 2. Stated willingness to comply with all study procedures and availability for the duration of the study
• 3. Male or female, aged 18 years and older.
• 4. Admitted to UVA hospital, or seen as an outpatient, or seen at Carrilion hospital.
• 5. Presence of diarrhea\*
• 6. Episode of C. difficile infection, non-severe or severe uncomplicated.
• 7. Within 120 hours of receiving standard therapy (oral vancomycin or fidaoxmicin).
• 8. Must be able to provide informed consent in person or electronically, or if not able to have a LAR to provide consent, in person or remotely via virtual or electronic means.

Exclusion Criteria:

• 1. At enrollment, presence of any of the following:
• 1. Hypotension or shock
• 2. Megacolon or moderate to severe ileus
• 3. Acute abdomen
• 4. Admission to intensive care unit
• 2. Inability to tolerate oral or enteral medication
• 3. Presence of other known infectious etiology of diarrhea
• 4. COVID-19 co-infection at the time of CDI diagnosis.
• 5. Absolute neutrophil count \<500 mcl
• 6. Within 100 days of hematologic or solid organ transplant
• • Inflammatory bowel disease (e.g. Crohn's disease, ulcerative colitis) or other etiology of non-infectious diarrhea. For patients with history of IBD, allow enrollment if disease is well-controlled and stable (not in flare).
• 7. Enrollment in another investigational drug trial
• 8. Current use of alternative treatment for CDI (e.g. antibiotics other than vancomycin or fidaxomicin; IVIg; fecal transplant).
• 9. On probiotics and not willing to discontinue.
• 10. Cirrhosis or in participants with ALT \> 3X normal
• 11. End stage renal disease, unless on dialysis(HD or PD) or creatinine clearance or estimated GFR of \<30mL/min even after adequate hydration
• 12. Life expectancy of \< 6 months.