Blastocystis sp.-An emerging cause of diarrhea post stem cell transplantation

Key Clinical MessageProtozoans are endemic in the Middle East and diarrhea workup post stem cell transplant should always include stool examination for ova and parasites. We present a case of Blastocystis sp. infection in a multiple myeloma patient who developed diarrhea on day five of post-autologous stem cell transplantation. Diarrhea is a major complication and a potential cause of mortality in this population. Testing for endemic protozoan is recommended.