What is the treatment for a mild C. difficile infection?

• A. Supportive care only
• B. Vancomycin PO
• C. Metronidazole PO
• D. Fidaxomicin

Answer: (C)

In mild (non-severe) Clostridioides difficile infection, the goal is to deliver an effective antibiotic directly to the colon where the toxin is produced. Metronidazole given by mouth achieves good intraluminal concentrations in the gut, is inexpensive, and has been shown to be effective for less severe disease. For these cases, a typical regimen is metronidazole 500 mg taken orally three times daily for about 10 days. If symptoms are more severe, or if there is treatment failure, or if metronidazole cannot be used, alternatives like vancomycin or fidaxomicin are preferred. While supportive care is important, it alone does not treat the infection.