1. Mycophenolate mofetil (MMF)-induced enterocolitis is the cause of diarrhea in this patient. MMF is an immunosuppressant frequently prescribed after solid organ transplantation and to treat renal, rheumatological and neurological disorders [1, 2]. Several gastrointestinal sideeffects of MMF, including nausea, vomiting, weight loss, and afebrile diarrhea, are well-recognized [3]. In adults, a rare MMF-induced enterocolitis has also been described that resembles Crohn’s disease and graft-versus-host-disease [4, 5].More recently, MMF-induced enterocolitis has been reported to occur in pediatric patients [6, 7]. The child presented here developed MMF-induced enetercolitis after a renal transplant. 2. MMF-induced enterocolitis is rare, especially in children, and several other entities should be ruled out before making this diagnosis. Infectious causes, idiopathic inflammatory bowel disease, celiac disease, and other enteropathies, should be considered. The patient presented here had no documented episodes of graft rejection in the post-transplant period and there were no symptoms associated with the transplant kidney. Upper endoscopy and colonoscopy were performed to rule out primary inflammatory gastrointestinal disorders, including inflammatory bowel disease, celiac disease and other enteropathies. A stool work-up was performed and was found to be negative for infectious causes of diarrhea. 3. MMF was tapered over a 1-week period and then discontinued. During the taper period, the patient was started on azathioprine 125 mg daily to prevent allograft rejection. His diarrheal symptoms began to improve by day 4 and were resolved at his follow-up examination 10 days after discharge. His renal function has remained stable. Once identified, patients with MMF-induced enterocolitis may benefit from treatment with alternative immunosuppressant medications to alleviate symptoms and mucosal injury while still preventing transplant rejection, as in the case presented here.