Diarrhea in colon cancer after surgery refers to the increase in the number of bowel movements and diarrhea after surgery. It may be caused by the disturbance of intestinal flora inside the gastrointestinal tract, because patients will drink laxatives before the surgery, which will lead to the disturbance of normal flora in the intestinal lining. After the surgery, some patients will have anal non-ventilation and abdominal distension. It is recommended to perform routine blood tests, and also to check abdominal plain film or abdominal CT to understand whether the intestinal canal is dilated and whether there is pneumatization. If necessary, oral antibiotics should be administered for treatment, and small intestinal decompression tubes can also be used for treatment. Diarrhea after surgery may be caused by intestinal dysfunction or shortening of the intestinal tract. Because the intestinal tract will be shortened after surgery, it may lead to a disorder of stool formation, resulting in thinning of the stool and diarrhea.