We are doing this research study to determine if taking vancomycin in addition to a broad-spectrum antibiotic will decrease the chance of developing recurrent Clostridium difficile infection.

To determine whether prophylactic use of oral vancomycin reduces the incidence of recurrent Clostridium difficile infection (RCDI) in hospitalized patients admitted from their home or another health care facility (HCF) who are exposed to concurrent broad spectrum antibiotics.

This is a randomized research study, which means that the treatment you get will be chosen by chance, like flipping a coin. You will have a 50/50 chance of receiving one of the following:

1. Group 1 (Treatment Group): single daily dose of vancomycin in liquid form (study medication).
2. Group 2 (Placebo Group): single daily dose of placebo (a placebo will look just like the study medication, but contains no medication, only a substance like sterile water).

Depending on the group you are placed in (which is chosen by a computer), you will receive either a daily dose of the study medication or a daily dose of the placebo for a total of ten days. If you are discharged from the hospital prior to ten days, you will be given the study medication to complete outside of the hospital with written instructions.

A member of the Research staff will monitor you daily during the 10 days of treatment for any adverse reactions or any signs and symptoms of recurrent Clostridium difficile infection. If you are discharged prior to ten days, the monitoring will take place via telephone call daily until completion of the ten day treatment.

You will be contacted again by telephone at 1, 3, and 6 months after completion of the study medication to inquire about your general health and any changes in health status.

Other medical information from your records and charts may also be collected by us for purposes of review for this study.

Inclusion Criteria:

1. In patients >19 years of age
2. History of C. difficile diarrhea within 16 weeks and treated with Flagyl or Vancomycin during last episode.
3. Patients started on antibiotics during current admission for any other indication at any point of time during hospital course.

Exclusion Criteria:

1. Current diagnosis of CDI
2. First episode of CDI during this admission.
3. Allergy to Vancomycin or other known intolerance
4. Pregnant

h) Patient has received broad-spectrum antibiotics for more than 48 hours for this admission j) Incarceration