Regular review after colorectal cancer surgery is the key measure to detect local recurrence and distant metastasis after colorectal cancer surgery as early as possible, and only early detection and correct treatment can improve the treatment effect and prolong the survival time of patients, so the importance of standardized follow-up after colorectal cancer surgery is self-evident. Because most of the recurrence and metastasis of colorectal cancer after surgery occur within 2 years after treatment, accounting for about 80%, therefore, close review is needed within 2 years and once in 3 months, while recurrence and metastasis of a few patients occur 3-5 years after treatment, accounting for about 10-20%, therefore, once in 6 months is sufficient for 3-5 years after surgery. Most of the tumors do not recur within 5 years after treatment, so the chance of recurrence is very small, so it is close to cure, which is about equal to clinical cure rate, so it is enough to review once a year after 5 years. According to the law of recurrence and metastasis after colorectal cancer surgery, the recommended follow-up plan for colorectal cancer after treatment according to the 2015 China Colorectal Cancer Diagnosis and Treatment Standard of Ministry of Health is as follows: 1. Medical history and health checkup, once every 3-6 months for 2 years, then once every 6 months for a total of 5 years, and once a year after 5 years. 2, Monitoring of CEA and CA199, every 3-6 months for 2 years then every 6 months for a total of 5 years and annually after 5 years. 3, Abdominal and/or pelvic ultrasound every 3-6 months for 2 years, then every 6 months for a total of 5 years, and annually after 5 years. Chest X-ray every 6 months for 2 years, and then once a year after 2 years. 4.CT or MRI of the chest, abdomen and/or pelvis once a year. 5.Colonoscopy within 1 year after surgery, if there is any abnormality, review in 1 year; if no polyp is seen, review in 3 years; then once in 5 years, any large intestinal adenoma that appears in the follow-up examination is recommended to be removed. If preoperative colonoscopy is not completed for the whole colon, it is recommended to perform colonoscopy 3-6 months after surgery. 6.PET/CT is not a routinely recommended test. Note: High risk refers to the pathology report suggesting risk factors such as lymphatic/vascular infiltration and poor differentiation. The absence of the above high-risk factors is classified as intermediate risk. However, it is not enough just to master the above follow-up review program, there are several details that need special attention, and neglect of details may lead to catastrophic consequences. Firstly, although colorectal surgeons know that colonoscopy should be repeated once a year after colorectal cancer surgery, it is often neglected for those who have not completed whole colon examination due to tumor obstruction before surgery to perform colonoscopy 3-6 months after surgery. In my clinical work, I have repeatedly encountered cases of colorectal cancer found by e-colonoscopy 1 to several years after colorectal cancer surgery, and when found, they are often not early, obviously the irregularity of colorectal cancer follow-up after colorectal cancer surgery leads to these saddening situations. Because colorectal multiple cancers account for 6-8% in clinical practice, if preoperative whole colonoscopy is not completed, the overall situation of the whole colon is not fully grasped, so the diagnosis may be missed. Early postoperative e-colonoscopy can detect other lesions as early as possible or remove polyps to prevent recurrence of bowel cancer. In addition to the postoperative 3 month e-colonoscopy, the following measures can be taken to avoid missed diagnosis. First of all, patients with colorectal cancer all undergo whole abdomen enhanced CT before surgery and carefully read the film before surgery to exclude multiple lesions other than known colon cancer lesions, and secondly, the whole colon should be explored intraoperatively to discover other lesions as well, and these two methods are very important because they are prospective in discovering multiple lesions and can be handled intraoperatively at the same time, which is most beneficial to patients. Postoperative 3 month e-colonoscopy is actually only a remedial method, which is obviously less significant than prospective diagnosis. Second, postoperative follow-up chest X-ray and ultrasound examination of abdominopelvic cavity should be replaced by CT of chest, abdomen and pelvis for colorectal cancer. Obviously, the value of chest X-ray and abdominopelvic ultrasound for early diagnosis of distant metastasis and local recurrence after colorectal cancer is very limited because chest X-ray cannot diagnose small-diameter occupying lesions in lung and abdominopelvic ultrasound examination is influenced by many subjective and objective factors, therefore, only enhanced CT examination can be used for early diagnosis of distant metastasis and local recurrence after colorectal cancer. Therefore, only enhanced CT can play an important role in the diagnosis of distant metastasis and local recurrence after colorectal cancer surgery, while the use of X-ray and abdominopelvic ultrasonography in the postoperative follow-up of colorectal cancer has not been recommended in the 2016 NCCN guidelines. Third, it is important to physically examine patients during postoperative colorectal cancer review. Postoperative review of colorectal cancer is not only blood test and various examinations, but also medical history and physical examination are very important. Through medical history, various postoperative complications can be targeted and treated in time to improve patients’ quality of life, while physical examination also plays an important role in diagnosis and treatment of complications. Therefore, colorectal surgeons should practice the “one finger technique”, and effective rectal diagnosis after rectal cancer surgery can also promptly deal with postoperative anastomotic stenosis and other anastomotic complications of rectal cancer. The anastomotic complications, especially for patients with low rectal cancer who have protective stoma after surgery, should be treated in a timely manner by regular postoperative rectal examination. In addition, abdominal physical examination can give early surgical treatment after early detection of postoperative abdominal wall hard fibroids in FAP patients, once the disease progresses, the timing of surgery is lost.