Rectal cancer stage IV is an advanced stage. Patients with stage IV rectal cancer have already had distant metastasis, which belongs to the advanced stage of this disease. Rectal cancer is one of the most common intestinal tumors in clinic, accounting for about 60%, of which low rectal cancer is the most common type. Generally speaking, stage IV rectal cancer has already shown distant metastasis, and the common metastatic sites are liver, lung, bone and brain, etc. Patients may suffer from malnutrition or malignant disease. In addition, patients with stage IV rectal cancer may have peritoneal metastasis, thus producing a large amount of cancerous ascites. Patients whose rectal cancer develops to stage IV should actively carry out surgical treatment, radiotherapy and chemotherapy to prolong the survival period of patients as much as possible.