The reasons why the bile duct drainage tube does not flow are as follows: 1. It can not flow or even flow less after the procedure, sometimes including on the 2nd day. This situation is due to the fact that less bile is secreted, so less bile is drained through the T-tube. However, after 24 hours, there is usually more bile drainage; 2. The drainage tube is not placed properly during the operation, and it is not completely placed in the common bile duct, so some bile may flow into the abdominal cavity; 3. The common bile duct is blocked during the suture, so the bile cannot flow into the drainage tube or into the intestine, and these cases need to be operated again. This situation can be observed on the day of surgery, but later when this problem occurs, it needs to be treated by surgical exploration.