Mycophenolate mofetil-associated collagenous ileitis in a kidney transplant recipient: A case report.

We report a case of mycophenolate mofetil-induced collagenous ileitis in a kidney transplant patient. A 38-year-old Chinese man who had received a kidney transplant 3 years earlier was admitted to our department for severe diarrhea and rapid weight loss. Infection studies were negative, and tumors were ruled out, so drug-induced factors were suspected. He had been taking mycophenolate mofetil for immunosuppression, which was then suspended, and he had a rapid resolution of diarrhea. Pathological findings of gastrointestinal endoscopy biopsy showed the presence of thickened collagen bands in the subepithelium of the terminal ileum. This is the first report of collagenous ileitis caused by mycophenolate mofetil in a patient with a kidney transplantation, adding another reversible cause to this rare condition. It is important for clinicians to recognize and treat it promptly.