Clinical Key Points

Asymptomatic patients with a positive C. difficile test (e.g. patients whose symptoms have spontaneously resolved without treatment after the test was sent but before results were received) should not receive treatment

Clinical status should be improving within 4-6 days

Failure to show improvement in 6 days is considered treatment failure and should prompt consideration of either a change in therapy (e.g. metronidazole to vancomycin) or an alternative diagnosis. No resistance to vancomycin has been documented in clinical isolates of C. difficile and failure to respond to treatment may be a sign of a co-existing intestinal illness rather than refractory CDI

Metronidazole IV is likely only to be beneficial in patients with a severe ileus or intractable vomiting in whom oral vancomycin might not reach the colon. While it is often added to oral vancomycin in severely ill patients, there are limited data in support of this approach

DO NOT use vancomycin IV for the treatment of CDI

Alternative therapies (e.g. probiotics, fecal microbiota transplantation, cholestyramine, intravenous immunoglobulins) should not be used routinely and are discussed here: