BACKGROUND: Faecal microbiota transplantation (FMT) from healthy donors is considered an effective treatment against recurrent Clostridium difficile infection. AIM: To study the effect of FMT via colonoscopy in patients with recurrent C. difficile infection compared to the standard vancomycin regimen. METHODS: In an open-label, randomised clinical trial, we assigned subjects with recurrent C. difficile infection to receive: FMT, short regimen of vancomycin (125 mg four times a day for 3 days), followed by one or more infusions of faeces via colonoscopy; or vancomycin, vancomycin 125 mg four times daily for 10 days, followed by 125-500 mg/day every 2-3 days for at least 3 weeks. The latter treatment did not include performing colonoscopy. The primary end point was the resolution of diarrhoea related to C. difficile infection 10 weeks after the end of treatments. RESULTS: The study was stopped after a 1-year interim analysis. Eighteen of the 20 patients (90%) treated by FMT exhibited resolution of C. difficile-associated diarrhoea. In FMT, five of the seven patients with pseudomembranous colitis reported a resolution of diarrhoea. Resolution of C. difficile infection occurred in 5 of the 19 (26%) patients in vancomycin (P < 0.0001). No significant adverse events were observed in either of the study groups. CONCLUSIONS: Faecal microbiota transplantation using colonoscopy to infuse faeces was significantly more effective than vancomycin regimen for the treatment of recurrent C. difficile infection. The delivery of donor faeces via colonoscopy has the potential to optimise the treatment strategy in patients with pseudomembranous colitis.