This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Anatomy
In cholangitis, the organism mostly responsible is 
Select and explain. 
A. E.coli, B. Streptococcus, C. E.histolytica, D. Clostridium
A: E.coli
Answer: A: E.coli 
Explanation: Ascending bacterial infection of the biliary ductal system with obstruction Most common cause is choledocholithiasis Most common organisms present in the bile in patients with cholangitis : E.coli (MC). Klebsiella pneumoniae, streptococcus faecalis & Bacteroides fragilis Ref: Sabiston 20th edition Pgno :1507