<p>Diarrhea is a common complication after pediatric kidney transplantation. While mycophenolate mofetil is an important and common cause of post-transplant diarrhea, diarrhea can result from infectious and other non-infectious causes. Many complications can result from severe diarrhea including acute kidney injury from dehydration. Other unique complications in transplant recipients include tacrolimus toxicity and acute rejection (from changes in immunosuppressive pharmacokinetics or dosing in response to the diarrhea). Therefore, a thorough evaluation is recommended for all pediatric patients with severe diarrhea to ensure that appropriate interventions are instituted, and risks of complications minimized. Our review describes the scope of the morbidity of diarrheal illness after transplantation, common causes, and newer insights in the management of diarrhea, both supportive and targeted to the underlying cause.</p> Graphical abstract <p></p>