The time to remove the drain varies from person to person, usually after 3 days after surgery, and it is necessary to choose whether to remove it or not according to the surgical situation, the amount of drainage fluid, the amount of fluid accumulation, etc.; the time can be significantly delayed in the case of serious diseases, even up to a few months. Drainage tubes are mainly used to drain fluid and gas from the thoracic and abdominal cavities, especially in postoperative patients. The time of removal is individualized and is usually evaluated three days after placement. If the amount of drainage is large, the drainage tube should be continued and the time of removal postponed; if the amount of drainage is very small, even close to 0 ml, and the fluid and gas have been basically eliminated after ultrasound and other imaging assessments, the removal of the drainage tube can be considered. There are some special types of drains in the clinic, such as T-tube drain used in choledochotomy, whose extraction time usually takes at least 2 weeks, and the longest one can be up to about 8 weeks. It should be noted that for postoperative patients such as low rectal anastomosis for rectal cancer and perineal surgery, even if the drainage flow is low, the extraction time usually needs to be appropriately delayed to prevent the incision from not healing, etc. For those who suffer from serious abdominal infections in the postoperative period, the extraction time of their drains may be delayed indefinitely, even for several months. The timing of drain removal should be decided by a regular professional physician and should be in accordance with medical advice. Those who carry drains should pay attention to the cleanliness and hygiene of the drains to avoid inducing drain-associated infections.