[Fecal microbiota transplantation for refractory Clostridioides difficile infection with Crohn's disease in an allogeneic bone marrow transplant recipient].

We report a case of a 15-year-old girl who developed refractory Clostridioides difficile infection (CDI) after allogeneic bone marrow transplantation (BMT). She was treated successfully with fecal microbiota transplantation (FMT). The patient who had aplastic anemia underwent allogeneic BMT from an HLA 1-locus-mismatched unrelated donor. Four months later, she developed gastrointestinal graft-versus-host disease (GVHD), and immunosuppressive treatment improved the GVHD. However, she developed CDI 5 months after BMT and experienced recurrence after that. Fifteen months after transplant, CDI relapsed despite discontinuation of immunosuppressive treatment; thus, she underwent FMT. Colonoscopy at the time of FMT revealed round aphthae, mainly in the ileocecum, and colonic biopsy revealed inflammatory cell infiltration and noncaseating epithelioid granuloma, which fulfilled the diagnostic criteria for Crohn's disease. Following FMT for CDI, she was treated with enteric budesonide and intravenous methotrexate for Crohn's disease. These interventions resulted in a marked improvement in both CDI and Crohn's disease. Twenty-eight months after FMT, both CDI and Crohn's disease remained in remission with oral mesalamine monotherapy.