Normally, the postoperative T-tube drainage of choledochal stones is about 200-300 ml per day. An important treatment for stones in the common bile duct is choledochotomy and lithotripsy with T-tube drainage. The stones are removed as cleanly as possible during the operation, and the wall of the common bile duct is sutured and the T-tube is properly placed after the operation. Normally, the postoperative T-tube drainage is about 200-300 ml per day of clear drainage fluid. If there is no bile drainage from the T-tube after surgery, you should first check whether the tube is dislodged or blocked; if too much bile is drained, check whether there is any obstruction at the lower end of the T-tube; if the bile is turbid, you should check whether there are stones remaining, biliary tract infection, and so on. If the bile duct is clear and there is no stone residue, the tube can be considered to be removed 4 weeks after open surgery, or an appropriate extension of time can be considered in case of laparoscopic surgery.