All patients will be given a journal in which they can record any symptoms of a C. difficile infection (i.e., diarrhea). Additionally, patients in Group C will record their kefir consumption on a daily basis. All patients will receive a follow-up phone call 3 days after their hospital discharge and weekly thereafter for 30 days (a total of 4 phone calls). Patients will be asked if they have had any incidence of diarrhea in order for nursing staff and physicians to assess if C. difficile infection has occurred.