Except for early-stage colorectal cancer (including colon and rectal cancer), patients with generally progressive disease require post-operative adjuvant chemotherapy (or radiation therapy). Chemotherapy requires six to eight cycles for about six months. If the combination chemotherapy is not tolerated, oral chemotherapy with Herodar can be used appropriately, together with herbal medicine and immunotherapy, which can also achieve good results. Among the patients with colorectal cancer who have received radical treatment, about 40% of them may have postoperative recurrence or metastasis after surgery, and another about 3% may have heterochronic colorectal cancer with multiple primary cancers, so patients with progressive stage should have adjuvant chemotherapy (or radiotherapy) and regular follow-up after surgery. Through postoperative follow-up, it is possible to achieve – early detection of recurrent lesions and early treatment in order to achieve better curative effect, secondly, to monitor the possible occurrence of heterochronous multiple primary cancers, and thirdly, to evaluate the effect of the first treatment. At the same time, the follow-up of colorectal cancer patients is a long-term process that requires professional skills and certain equipment to achieve the above goals and processes. Therefore, a reasonable follow-up plan must be carefully formulated according to the possibility of postoperative recurrence of colorectal cancer patients and the accuracy, sensitivity and cost of various follow-up tools. Post-operative follow-up plan for colorectal cancer patients: The post-operative follow-up plan for colorectal cancer patients should take into account the patient’s condition, prognostic factors and whether to receive post-operative adjuvant therapy. For patients who cannot receive adjuvant therapy after surgery, the following follow-up plan can be arranged: once every three months for 2 years after surgery, and once a year for colonoscopy to detect heterochronous cancer and anastomotic recurrence; for 2-5 years after surgery, the follow-up can be extended to once every six months; for patients who are more than 5 years after surgery, the follow-up can be once a year or combined with health checkup to do additional key items. For patients who received adjuvant chemotherapy after surgery, blood routine and CEA measurement can be increased to once a month in combination with chemotherapy, and after chemotherapy, follow up according to the aforementioned plan. Postoperative follow-up of colorectal cancer: I. Medical history and physical examination: It is valuable to conduct regular follow-up and physical examination for postoperative patients. Usually, patients found in physical examination have symptoms or abnormal blood test. It is generally believed that any clinical relapse that is symptomatic and can be confirmed by physical examination is often incurable. Stool occult blood test: the positive rate is about 10%. Liver function test: because liver is the most likely site of colorectal cancer metastasis. Colonoscopy: It can be used to detect recurrent and heterochronic colorectal cancer multiple primary cancers in the lumen of large intestine. V. Chest X-ray: It can detect asymptomatic lung metastasis lesions. VI. Abdominal ultrasound: It can provide a comprehensive understanding of the important organs and lymph nodes in the abdominal cavity and pelvis. Tumor markers: the main tumor markers for postoperative monitoring of colorectal cancer are carcinoembryonic antigen (CEA). It is sometimes the first indicator of recurrence, which can be 6 months earlier than other indicators.