All patients will start therapy with vancomycin for four days before of stratification, with random allocation (1 to 1) to one of the two treatment schemes: 1) FMT, with the infusion in the cecum - through the biopsy channel - of 60-120 gr (depending on production) of donated feces, obtained from the donor within 6 hours from transplantation, and manually homogenized in 100/200 ml of physiological solution; or 2) standard vancomycin-based therapy according to the international recommendations. Colonoscopy will be performed by an expert endoscopist, with mucosal biopsy (when possible) for histology examination. Patients allocated to FMT arm will undergo preparation for colonoscopy (four liters of a solution with saline laxatives). All patient will be instructed on hygiene rules to be followed at the patient's domicile to avoid re-infections at home. Stool donors should preferably be patient's relatives or intimates, must not have taken antibiotics in the last 6 months, should not present significant intestinal symptoms of other intestinal diseases and must result negative at the serum screening for viral hepatitis, AIDS or syphilis. Their stool will be tested for C. difficile, enteric bacteria, intestinal protozoa and helminthes pathogens.