A Novel Culprit in a Patient with Budd-Chiari Syndrome.

Budd-Chiari syndrome (BCS) is an uncommon illness that is characterized by obstruction of hepatic venous outflow. Patients typically present with nausea, vomiting, and abdominal pain, which can further progress into signs associated with liver failure, including jaundice, encephalopathy, and coagulopathy. The most common causes of BCS include pathologies that induce portal vein thrombosis, such as myeloproliferative disorders, malignancy, and acquired hypercoagulable states. In this case report, a patient who presented with abdominal pain and distention is diagnosed with BCS caused by an unusual etiology. He was found to have significant eosinophilia, prompting additional evaluation for parasitic infections. Using stool diagnostics/studies, he was found to have Dientamoeba fragilis trophozoites. The patient was treated with enoxaparin, warfarin, and metronidazole with a resolution of his symptoms. This case outlines a novel cause of BCS as well as the proposed mechanism of Dientamoeba fragilis induction of BCS.