After 11 days of colon cancer surgery, there is still drainage fluid which is mainly purulent secretion, it is normal situation, no need to worry too much. After colon cancer surgery, drainage tube is put in for drainage, mainly to prevent anastomotic fistula, meanwhile, by observing the color and flow rate of the liquid out of the drainage tube, we can judge the recovery of patient’s condition and complications, which can help to cure the disease better. Usually the drainage fluid outflow will last for 2-3 weeks after surgery, pay attention to clean the fluid to avoid infecting the wound. After surgery, a drainage tube is left to drain, which can prevent the purulent secretions appearing in the wound recovery from staying in the body and forming ascites, avoiding aggravation of the condition and favoring the recovery of the disease. After surgery, patients should pay attention to light diet, avoid spicy, stimulating food, reduce the stimulation of the wound. It is recommended to actively follow the doctor’s instructions to cooperate with the treatment.