<prompt> What is the most common cause of pyogenic liver abscessTraumaBiliary tract infectionColonic DiveiculitisAppendicitis  <response>: Routes of infection Biliary tract Most Common - CBD stones leading to cholangitis, Hilar carcinoma in Western countries, CBD strictures Poal vein 2nd most common Hepatic aery - Hematogenous spread, usually monimicrobial, Staphylococcus or streptococcus Direct extension- from subdiapragmatic abscess, from suppurative cholecystitis, from empyema in chest, from perinephric abscess Penetrating or blunt trauma Cryptogenic Ref: Sabiston 20th edition 