Inflammatory bowel disease (IBD) is a chronic relapsing disorder of the intestine of unclear etiology. Increasing evidence has pointed to intestinal dysbiosis as a potential factor in a genetically susceptible individual. Fecal microbiota transplantation (FMT) has been used to treat inflammatory bowel disease with variable degrees of success. Herein, we report a patient with Crohn's colitis, previously failing an immunosuppressant, who achieved clinical, endoscopic, and histologic remission after a single fecal microbiota transplantation infusion. We have further characterized the changes in the fecal microbiota associated with this observation.