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. Poal vein was not visualized on ultrasonography. Liver function tests were normal and endoscopy revealed esophageal varices. The most likely diagnosis is:
Kala azar with poal hypeension Poal hypeension of unknown etiology Chronic liver disease with poal hypeension Poal hypeension due to extrahepatic obstruction