Vancomycin for C Difficile NAAT+/EIA- Hematology Oncology Patients

Inclusion Criteria: * Patients admitted to the hematology oncology inpatient units at Froedtert Memorial Lutheran Hospital * New onset of diarrhea during hospitalization * C. difficile clinical testing showing NAAT positive EIA negative results Exclusion Criteria: * Being unable to consent for self * Inability to take enteral medications * Unwillingness to enroll in study * Patient has a documented allergy to vancomycin * Patient has a documented life expectancy shorter than treatment course (14 days) * Patient is unwilling or unable to provide stool samples in the outpatient setting after discharge * Diagnosis of C. difficile colitis \[NAAT (+) and toxin EIA (+) within 3 months of enrollment). * New onset of abdominal distention within 24 hours prior to the onset of diarrhea during index admission * Presence of toxic megacolon * Presence of clinical sepsis. Sepsis will be defined as a Sequential \[Sepsis-related\] Organ Failure Assessment (SOFA) score of 2 points or more as per 2016 definitions * Pregnancy or lactating