Resistance to metronidazole or vancomycin has not been conclusively documented.
Recurrent disease after a complete course of therapy occurs in ~25% of patients. Relapse is due to a failure to eradicate spores (60%) or acquisition of a new strain (40%). Document recurrent disease with repeat stool testing and clinical symptoms suggestive of C diff.
Repeat C diff testing to assess for cure is strongly discouraged. Only repeat C diff testing if clinical signs/symptoms suggest relapsed infection.
Some patients may develop irritable bowel syndrome after infectious colitis including CDI. This may be suggested by recurrent symptoms with negative stool testing.
Vancomycin 125 mg q6h should be given if metronidazole was used for the first episode.
Use a prolonged tapered and pulsed vancomycin regimen if a standard regimen was used for the initial episode
Second recurrence should be treated with vancomycin taper followed by pulse dosing.
Vancomycin Taper Regimen
If serious or multiple recurrences, ID consult is advised for consideration of Fecal Microbial Transplant.