Low rectal cancer is different from colorectal cancer in other areas in terms of anatomy and diagnosis, and should have its own special features in diagnosis and treatment, but there is no real diagnosis and treatment guideline in clinical practice so far, so each medical unit often acts separately in surgical treatment, and even different treatment teams in the same hospital have opposite treatment methods. Experience instead of standardization and clinical innovation instead of updating treatment methods have caused a lot of confusion among many physicians regarding the surgical treatment of low rectal cancer. It is important to discuss the standard of surgical treatment for low rectal cancer to improve the efficacy of low rectal cancer, reduce patient trauma and improve patient survival quality. 3. Confusion and strategies of surgical treatment of low rectal cancer There are many confusions in the treatment of low rectal cancer, such as how to choose anus-preserving surgery or non-anus-preserving surgery, whether to use prophylactic stoma when preserving anus, and the choice of non-anus-preserving surgical methods. 3.1. The choice between anus-preserving surgery and non-anus-preserving surgery Non-anus-preserving surgery means permanent artificial anus, which not only reduces the quality of life for rectal cancer patients, but also may cause great impact on psychological and physiological aspects. While the quality of life is better with the possibility of defecation from normal anus after anal preservation surgery, and the psychological and physiological impact on patients is less, the partial loss of defecation function caused by the surgery, and the chemotherapy and radiotherapy before and after surgery still have a greater impact on the defecation function of patients. There is no unified standard for when to use anus-preserving surgery for low rectal cancer and when to use non-anus-preserving surgery, and even for patients with the same site and stage, different physicians may use different surgical methods. Most colorectal surgeons use the criteria based on the distance of the lower edge of the tumor from the anal verge. The closer the lower edge of the tumor is to the anal verge, the lower the chance of anus preservation, and it has a great relationship with the experience of the surgeon. In addition to the distance of the lower edge of the tumor from the anal verge, the factors affecting the choice of surgical approach are also related to the appropriate imaging staging and the histopathological findings of the specimen at the time of surgery. The earlier the staging, the higher the chance of anus preservation. If there are still tumor cells remaining in the frozen pathological examination of the cut edge after the maximum severance of the distal intestinal segment of the tumor, the patient loses the chance of anus preservation. Therefore, the staging of the tumor should be fully evaluated and the location of the tumor should be accurately measured when choosing the surgical approach, and the choice should also be made based on the pathological findings of the surgical margins after surgery. Some scholars suggest to classify low rectal cancer and adopt standardized surgical methods accordingly: Class I low rectal cancer is rectal cancer above the anal canal, and the distance between the lower edge of the tumor and the upper edge of the internal sphincter is greater than I cm, and this type of rectal cancer adopts anal preservation surgery recto-anal anastomosis; Class II low rectal cancer is rectal cancer at the junction of the rectum and anal canal, and the distance between the lower edge of the tumor and the upper edge of the internal sphincter is less than 1 em. This type of rectal cancer requires partial internal sphincter resection; HI low rectal cancer is rectal cancer in the anal canal and the tumor infiltrates the internal sphincter, this type of rectal cancer requires total internal sphincter resection; 1V low rectal cancer is rectal cancer outside the anal canal and the tumor has invaded the external anal sphincter, this type of rectal cancer must perform non-anal preservation surgery. In conclusion, the indications for non-anal preservation surgery are low rectal cancer tumors invading the external anal sphincter or anal levator muscle. In addition, patients with positive tumor cells on frozen pathological examination of the lower cut edge of rectal tumor specimens are also indications for non-anal preservation surgery. Theoretically, for resectable low rectal cancer, except for non-anal-preserving surgery, all of them can be operated with anal preservation. 3.2 Whether to use prophylactic stoma at the same time of anus-preserving surgery Postoperative anastomotic leak in rectal cancer is a serious complication of anus-preserving surgery, which can lead to patient’s death in serious cases. Meanwhile, because of the high incidence of postoperative anastomotic leak (even up to 20% or more in the literature, colorectal surgeons attach great importance to the prevention of anastomotic leak. While the incidence of anastomotic leak is not significantly related to prophylactic stoma, the impact of anastomotic leak on the body is much less severe when it occurs after prophylactic stoma. What is confusing to physicians is which patients develop anastomotic leak after surgery? Because of this, many scholars have emphasized that prophylactic stomas, also called protective stomas or de-functionalized stomas, should be routinely performed to avoid the severity of anastomotic leaks when they occur. However, the impact of prophylactic ostomy itself on the patient is obvious, as it not only causes inconvenience to the patient during the ostomy period, but also complications of the ostomy itself and postoperative stoma reentry surgery. Therefore, the author does not recommend prophylactic stoma for all low-grade rectal cancers, but only for patients with higher risk. There is no uniform standard for assessing the risk level of anastomotic leak, and each hospital and physician has their own experience. The author advocates that if there are 2 non-technical factors (including advanced age >70 years. malnutrition, systemic underlying disease, radiotherapy, oversized tumor, male patients, and obesity) or 1 technical factor (poor anastomosis, anastomotic blood flow disorder, and presence of anastomotic tension) should undergo prophylactic ostomy. If no risk factors are present, postoperative anastomotic leakage can be largely prevented by placing an anal tube drainage alone. Of course, we currently also use modified de-functionalized stoma techniques, such as tubular catheter diversion technique at the end of the ileum or fecal diversion technique above the rectal anastomosis, and the application of these techniques can avoid stoma and later reoperation, and their clinical application is being summarized. 3.3. Surgical choice of non-anal preservation surgery The classic surgery of non-anal preservation surgery is combined abdominal perineal resection, but some studies have concluded that: the postoperative survival rate of traditional combined abdominal perineal resection for rectal cancer is lower than that of anal preservation surgery under the principle of total rectal mesorectal resection, and the postoperative recurrence rate is also higher. Therefore, many scholars suggested to abolish the traditional combined abdominoperineal resection and perform an extended combined abdominoperineal resection instead. The combined extra-anal levator perineal resection was first proposed in many European countries, and it is also called columnar resection because the resected rectal specimen does not have a thin waist-like form but a columnar structure. However, many scholars found in the process of implementing this technique that there are many problems in this technique itself, mainly in the form of excessive pelvic floor defect, the need for postoperative transfer of myocutaneous flap, and the complication heart of high incidence of perineal infection, so the promotion of this technique is limited, especially in China, the vast majority of scholars do not advocate the adoption of this technique than, but believe that the scope of resection should be individualized according to the extent of tumor invasion, in order to maximize the preservation of perineal tissue. The author also advocates the adoption of individualized resection scope. Recently, the author is exploring the expanded perineal combined rectal cancer resection with perineal approach under folding knife position, which can resect the perineum and pelvic floor under direct vision, which can ensure the negativity of the circumferential incision margin and reduce the intraoperative rectal rupture rate, and also can protect the pelvic floor tissues to the greatest extent and reduce the complications of pelvic floor defects, which has great advantages compared with the traditional abdominal perineal combined rectal cancer resection. This technique is also being summarized and certainly needs to be confirmed by multicenter and prospective studies. In conclusion, the diagnosis and treatment of low rectal cancer has its own special characteristics, and it should be treated as a separate category of disease in the clinical diagnosis and treatment process, and experience and lessons learned should be continuously summarized to optimize the treatment technology. The ultimate goal is to improve the survival rate while minimizing the trauma and improving the quality of patients’ survival.