Wasting after colon cancer surgery is abnormal, which is mainly related to insufficient postoperative nutrition supply, auxiliary radiotherapy and other factors. 1. Insufficient postoperative nutrition supply: after colon cancer surgery, patients need to combine enteral and parenteral nutrition support, if the nutrition supply or intake is insufficient, patients may suffer from weight loss and wasting, and need to supplement nutrition in time. 2. Adjuvant radiotherapy: after colon cancer surgery, patients may need to receive intraperitoneal catheter infusion chemotherapy, intravenous chemotherapy, etc. Chemotherapy drugs may cause nausea, vomiting, diarrhea and other adverse reactions, which may lead to weight loss. Radiotherapy for residual lesions after colon cancer surgery may cause adverse reactions such as radiation dermatitis and radiation colitis, leading to gastrointestinal dysfunction, thus causing weight loss. It is suggested that if any abnormal situation occurs after colon cancer surgery, one should seek medical treatment in time to avoid serious consequences.