Budd-Chiari syndrome is caused by hepatic venous outflow obstruction, resulting in hepatomegaly, ascites, right upper quadrant pain, and liver dysfunction. It may be due to thrombosis or compression of the hepatic veins or IVC.

According to Rumack’s Diagnostic Ultrasound:

“Budd-Chiari syndrome results from hepatic venous outflow obstruction and presents with hepatomegaly, ascites, and right upper quadrant pain.”