A 58-year-old female develops watery diarrhea, abdominal cramping, and fever 5 days after completing a course of clindamycin for cellulitis. Stool testing confirms Clostridioides difficile infection (CDI) of moderate severity. Which of the following is the most appropriate initial treatment?
✓ Correct Answer: Option C
For an initial episode of non-fulminant C. difficile infection, oral vancomycin (or oral fidaxomicin) is the recommended first-line treatment. Oral metronidazole is less effective and no longer preferred for moderate disease.