Inclusion Criteria:  age ≥18 years multiple recurrent CDI (≥2 previous episodes of CDI) at least 3 or more loose or watery stools (Bristol 5-7) per day a positive Glutamate Dehydrogenase (GDH)-enzyme and positive CDI toxin A and/or B test the patient or the legal guardian sign the written informed consent  Exclusion Criteria:  pregnancy or breastfeeding ongoing antibiotic treatment fulminant CDI previous FMT immunodeficiency need of intensive care requirement for vasoactive drugs other cause of diarrhea inflammatory bowel diseases irritable bowel syndrome life expectancy shorter than 3 months unavailable for follow-up visits