Blood in the stool half a month after colon polyp surgery may be caused by colon surgery, or may be caused by wound rupture and infection, the cause should be clarified and then treated symptomatically. 1. Colon surgery: When you have colon surgery, it stimulates the digestive tract, causes excessive secretion of gastric acid in the stomach, contacts the gastric mucosa or intestines, and causes bleeding symptoms, and then there will be blood in the stool half a month after colon polyp surgery. 2. Wound rupture infection: half a month after colon polyp surgery, due to environmental stimulation or defecation led to wound rupture, blood in the stool. Half a month after colon polyp surgery, blood in the stool, if the amount of bleeding is not large, usually normal, do not need to worry too much, by adjusting the diet, control defecation, pay attention to wound hygiene can be relieved, if the amount of bleeding is large, it is recommended to go to the hospital in a timely manner, to clarify the cause of bleeding, to avoid the development of the disease, endangering the health of the body.