A 7 year old girl from Bihar presented with three episodes of massive hematemesis and melena. There is no history of jaundice. On examination, she had a large spleen, non-palpable liver and mild ascites. Portal vein was not visualized on ultrasonography. Liver function tests were normal and endoscopy revealed esophageal varices. The most likely diagnosis is –
Kala azar with portal hypertension Portal hypertension of unknown etiology Chronic liver disease with portal hypertension Portal hypertension due to extrahepatic obstruction