If the possibility of localized fluid accumulation in the body can be excluded, such as peritoneal effusion, pleural effusion, etc., weight gain after colon cancer surgery is considered to be a good phenomenon. Weight gain after colon cancer surgery may be related to good absorption and metabolism of the body after surgery, basic recovery of intestinal function and better absorption of nutritional status, so weight gain after colon cancer surgery is a sign of good recovery after surgery. However, if localized fluid accumulation occurs in the body, such as peritoneal fluid accumulation, pleural fluid accumulation and other symptoms, weight gain may also occur, and ultrasound, CT and other examinations can be conducted to determine whether weight gain is caused by localized fluid accumulation in the body. It is recommended that postoperative colon cancer patients should have regular checkups and pay attention to nutritional supplementation, and if localized fluid accumulation occurs, they should be treated under the guidance of professional doctors.