Screening to Prophylax Against Clostridium Difficile Infection -

Screening to Prophylax against CDI (SToP CDI) is a prospective, single-center,
double-blinded, randomized, placebo-controlled study of the effectiveness of vancomycin vs.
placebo for preventing CDI in patients colonized with toxigenic C. difficile and receiving
high-risk antibiotics. The investigators plan to screen 2500 patients to randomize 200.

Consented patients will have a stool sample collected and tested for presence of toxigenic C.
difficile by PCR. Patients who test negative will simply be followed for development,
severity and outcome of CDI. Patients who test positive (are colonized with C. difficile)
will be randomized to one of two arms:

Arm 1: Patients receive 125 mg vancomycin PO q6 hours as prophylaxis against C. difficile for
the duration of their antibiotic treatment +3 days.

Arm 2: Patients receive placebo PO q6 hours for the duration of their antibiotic treatment +3
days.

Inclusion Criteria:

1. Expected duration of admission sufficient to complete screening and enrollment

2. Age ≥18

3. Able to give informed consent

4. Initiated on one of the following antibiotics within the prior 72 hours with an
expected duration of at least 72 hours from enrollment: clindamycin, ampicillin,
ampicillin/sulbactam, amoxicillin, amoxicillin/clavulanate, moxifloxacin,
levofloxacin, piperacillin/tazobactam, or any cephalosporin

5. Maximum expected duration of antibiotics 8 weeks

6. Able to take oral study medications

7. Able to provide a stool sample during hospitalization or within 3 days of discharge

8. Reasonably expected to be able to complete follow up

Exclusion Criteria:

1. Chron's disease, ulcerative colitis, celiac disease, or other chronic diarrheal
illness

2. CDI within prior 90 days

3. Currently on metronidazole, oral vancomycin, rifaximin, fidaxomicin, or any other
antibiotic active against C. difficile

4. Current diarrhea

5. Current ileostomy, colostomy or other form of surgically disconnected gut such that
oral therapy would not be expected to reach the entire lumen of the gut

6. Pregnancy or breast feeding (determined prior to randomization)

7. Travel to an area of endemic diarrheal illness within the last 30 days

8. Life expectancy of less than 60 days

9. Known allergy to vancomycin

10. Participation with other research trials that could impact the results of this trial
within the last 30 days

11. Previously enrolled in this study