<prompt> Most common cause of cholangitisViral infectionCBD stoneSurgeryAmoebic infection  <response>: Cholangitis Ascending bacterial infection of the biliary ductal system with obstruction Most common cause of acute cholangitis is choledocholithiasis Most common organism present in the bile in patients with cholangitis : E.coli, Klebsiella pneumoniae, streptococcus faecalis Bacteroides fragilis Etiology CholedocholithiasisMC Benign strictures Biliary enteric anastomotic strictures Cholangiocarcinoma and periampullary cancer Ref: Sabiston 20th edition Pgno :1507 