Alanyl-glutamine for CDI

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 > 65 years

4. Admitted in the hospital

5. Presence of diarrhea*

6. Stool positive for C. difficile tcdB and TcdB

7. 1st episode of C. difficile infection, non-severe or severe uncomplicated

8. Within 48 hours of receiving standard therapy (oral vancomycin at UVA)

Exclusion Criteria:

1. At enrollment, presence of any of the following:

- Hypotension or shock

- Megacolon or moderate to severe ileus

- Acute abdomen

- Admission to intensive care unit

2. Inability to tolerate oral or enteral medication

3. Presence of other known infectious etiology of diarrhea

4. Inflammatory bowel disease (e.g. Crohn's disease, ulcerative colitis) or other etiology of non-infectious diarrhea

5. Enrollment in another investigational drug trial

6. Current use of alternative treatment for CDI (e.g. antibiotics other than vancomycin or fidaxomicin; IVIg; fecal transplant).

7. On probiotics and not willing to discontinue.

8. Cirrhosis or in participants with ALT > 3X normal

9. End stage renal disease, on dialysis, or creatinine clearance or estimated GFR of <30mL/min even after adequate hydration

10. Life expectancy of < 6 months.