Possible reasons for weight loss after accidental gallbladder cancer surgery include reduced digestive ability and absorption disorder after surgery, and the occurrence of metastasis of malignant tumors cannot be excluded. 1. Reduced digestive ability and absorption obstacle after operation: if gallbladder cancer has invaded common hepatic duct, partial choledochotomy and bile-intestinal anastomosis need to be performed, that is to say, the normal digestive tract structure will be damaged, the digestive tract will be reconstructed, and the absorption ability of nutrients will be reduced, so weight loss may occur. 2. Metastasis of malignant tumors: gallbladder cancer is of high malignant degree, and metastasis will occur in the late stage, and the metastatic sites include liver, lungs, duodenum, lymph nodes and other parts. If weight loss is caused by tumor metastasis, it is necessary to consult doctor in time to improve relevant examination.