Have you used oral vancomycin as prophylaxis for C difficile infection in patients admitted for allogeneic hematopoietic cell transplant?

How would you manage prophylaxis for C. difficile infection in allogeneic hematopoietic cell transplant patients?

• I would use oral vancomycin as primary prophylaxis in patients without a history of C. difficile infection, starting at the time of broad-spectrum antibiotic administration
• I would use oral vancomycin as secondary prophylaxis only in patients with a history of C. difficile infection in the previous year, starting at the time of broad-spectrum antibiotic administration
• I would use oral vancomycin as secondary prophylaxis for any patient who has previously developed a C. difficile infection, administered concurrently with broad-spectrum antibiotics
• I would not use oral vancomycin for C. difficile prophylaxis in these patients
• Other