The anus, as an organ of stool control above the GI tract, is completely different from the concept of the GI tract in the general sense. Anatomically and physiologically, it includes the lower rectum, the anal canal, and the neuromuscular structures that control defecation and the corresponding sensations. The effective preservation of this organ not only has a great impact on the patient’s quality of life, but also on the patient’s social activities and self-esteem. Due to the commonness of rectal cancer, the concept of anal preservation initially began with rectal tumor surgery. In 1908, Miles’ paper on combined abdominoperineal resection for rectal cancer changed the pattern of rectal cancer treatment, and many rectal cancer patients’ lives were saved, but it also brought another problem, namely the pain of losing the anal organ for bowel control. The Dixon procedure is now widely used in clinical practice; except for very low rectal cancer, about 85%-90% of rectal cancer patients can get the chance to preserve anus, although there are still >10% of patients who lose the chance to preserve anus due to various reasons. In recent years, with the rapid development of modern medicine, more techniques and management measures are available for cases that were previously difficult to preserve anus, such as the increase in the number of early-stage rectal cancer cases, which increases the chance of anus preservation, such as preoperative neoadjuvant radiotherapy for rectal cancer patients, and surgery after the tumor is downgraded to a lower stage, which can increase the rate of anus preservation. The modern concept of anal preservation has also developed from simple anal preservation surgery to an academic system of anal preservation, which is not limited to malignant tumors of the rectum, but for all diseases that bring about anal function problems, such as complex anal fistula, ulcerative colitis, etc. Even malignant tumors, such as malignant lymphoma of the rectum, can be cured by non-surgical anal preservation through radiotherapy and targeted therapy. Then a comprehensive grasp of modern medical technology and reasonable in designing anus-preserving treatment for patients becomes an important basis for increasing the chances of anus preservation. Anal preservation surgery is different from the general sense of gastrointestinal resection and reconstruction surgery in that it is considered from the perspective of preserving an important organ that would otherwise lead to disability, so how to make the best possible medical assessment and decision will be of great significance to the patient. In recent years, the authors have explored how to further improve the rate of anal preservation. 141 patients with rectal cancer were admitted to their department in the past 3 years, and only 4 cases did not obtain anal preservation, and the rate of anal preservation reached 98.2%, many of which were considered not to be preserved elsewhere. In all cases that reached the limit of anal preservation, there was no increase in local recurrence rate due to anal preservation, thus achieving an improvement in The quality of life was improved while preserving life. The following is the philosophy and practice of how to make the anal preservation rate reach its limit: Jianping Zhou, Department of Geriatric Medicine, Second Xiangya Hospital 1, the limit achieved in diagnosis, preoperative assessment and treatment decision: Patients should focus on the comprehensive assessment of both local and systemic aspects during consultation. In addition to assessing the nature of the tumor and the distance from the anal verge, the local situation should also include the depth of tumor infiltration, local lymph node metastasis, the degree of tumor differentiation and the regression of the tumor after preoperative radiotherapy, for example, if the tumor does not descend after the effect of preoperative neoadjuvant therapy, it often suggests that the prognosis of the tumor is poor and the possibility of anal preservation basically does not exist. For example, if a patient has COPD and his respiratory function is seriously impaired, even if he can undergo local radical resection, his systemic condition cannot tolerate the surgery, thus he can only adopt palliative anus preservation treatment. The author met a case of rectal cancer combined with isolated intracranial metastasis, and the treatment was as follows: Gamma knife treatment for intracranial metastasis, and radiotherapy for rectal lesion, and the disease has been controlled stably for four years of continuous follow-up. 2, the lesion and the anal edge distance limit: benign diseases such as ulcerative colitis, lateral developmental polyps even if the lesion is on the tooth line can be done to preserve the anus, malignant tumors such as malignant lymphoma, can be considered for radiotherapy. Therefore, the so-called distance consideration is mainly for progressive rectal cancer, early stage tumors are generally not subject to this restriction. In the past, it is usually considered that the tumor is not less than 2 cm from the dentate line, <3 cm in diameter, or less than 1/2 of the intestinal circumference, which can be pushed, and there is no infiltration of peri-cancerous tissue. However, with the development of preoperative radiotherapy, very most of the tumors will get downgraded, and it is now considered that the distance of tumor from dentate line can be reduced to 1 cm or less, while more attention is paid to the lateral cut margin. 3. To achieve the limit in treatment methods: whether other treatments are reasonably used besides surgery. At present, neoadjuvant radiotherapy has been used as a routine treatment for progressive low-grade rectal cancer, and more than 90% of patients have achieved remission of local lesions through preoperative treatment, and a very small number of cases have achieved permanent remission. For example, after total colectomy, when the J-pouch of ileum is anastomosed with the anal canal, the problem of too short small intestinal mesentery will be encountered, which requires proper trimming of the small intestinal mesentery vessels. If we do not have a good grasp of the cutting technique, the anastomosis will be changed to ileostomy due to the tension of the anastomosis. 4. Management and decision making: In practice, both doctors and patients have great requirements for anal preservation, but in the end, there are often objective problems in hospital management and decision making, such as no multidisciplinary consultation system, no radiotherapy equipment, poor deep lighting conditions in the operating room, lack of deep operating instruments, no good hemostatic equipment, etc. These guarantees are essential for extreme All these guarantees are necessary for extreme anal preservation. This system not only requires doctors to have a comprehensive knowledge of modern medicine related to anal preservation, but also requires hospitals to provide relevant management and modern equipment as a guarantee, so that the dual requirements of life extension and quality of life can be perfectly achieved. At this level, whether a patient has access to anal preservation or not, our decisions and thinking will determine to a great extent the patient's future.