Drainage fluid that is still abundant 40 days after surgery should be treated symptomatically in relation to the nature of the drainage fluid. If the drainage fluid is clear and light blood, it may be caused by a larger operation with a large postoperative wound and more localized exudate. The amount of drainage fluid will gradually decrease over time. If the drainage fluid is bloody, there is the possibility of bleeding from the abdominal organs, which requires prompt hemostatic treatment, and another operation may be needed when hemostasis is ineffective. When a gastrointestinal fistula occurs, the drainage fluid is yellow, the drainage fluid may be digestive fluid leakage into the abdominal cavity, this time the drainage fluid is more, through a long period of time through the drainage can often be cured. If there is more drainage fluid for a long time after surgery, more than normal, you should go to the hospital, complete the examination, understand the cause of the disease and follow the doctor’s instructions to be treated accordingly.