All acute biliary pancreatitis and complications in our hospital were diagnosed according to the Atlanta pancreatitis classification (as revised in 2012). The presence of gallstones with or without choledocholithiasis was confirmed by imaging examination. All patients underwent ERCP lithotomy and preventive pancreatic stent placement, and pancreatic juice was obtained for bacterial culturing and drug sensitivity testing. The included patients were older than 18 years old. We included patients with a first-time AP infection and those with AP who could be followed-up for 6 months.