- History of at least ≥ 2 recurrent CDI within 180 days where recurrence is deﬁned as return of diarrhea consistent with CDI within 8 weeks following CDI symptom resolution for at least 24 hours after a minimum of 10-day course of standard antibiotic therapy for each episode and/or ongoing symptoms consistent with CDI* (defined below) despite at least 7 days of treatment using oral vancomycin at a minimum dose of 250 mg po four times daily.