Ms. Jin from Xinjiang was diagnosed with rectal cancer, and because the tumor was located very close to the anus, she was told by many hospitals that surgery to remove the tumor required excavation of the anus, and that she could only defecate through a fistula in the future. Thinking about the inconvenience of future life and the gloom of tumor recurrence, Ms. Jin was almost desperate for life. Among colorectal cancers in China, rectal cancer accounts for about 60%, and low rectal cancer is common, and most of the masses can be palpated in rectal finger examination. Surgery is still the most critical means of treating rectal cancer, but in the past, for tumors whose lower edge is <5cm from the anal edge, transabdominal perineal colectomy was routinely performed, which required excavation of the anus, and patients could only defecate and exhaust through the fistula in the abdomen after surgery, which seriously affected the quality of life. < p="">Tumor, conventional combined transabdominal perineal resection, requires excision of the anus, and the patient can only defecate and vent through a fistula in the abdomen after surgery, which severely affects quality of life. <--> Tumors that are routinely treated with a combined transabdominal perineal resection, which requires excision of the anus, and the patient can only defecate and vent through a fistula in the abdomen after surgery, which seriously affects the quality of life. <--> For this kind of ultra-low colorectal cancer with the lower edge of the tumor less than 2cm from the dentate line (<5cm from the anal verge), it is impossible to preserve the anus by traditional surgery, which is solved by laparoscopic internal sphincter resection (ISR) in the general surgery department of Yangpu Hospital of Tongji University. For patients whose tumor local infiltration is limited to the rectal wall or the internal sphincter, after surgical removal of the internal sphincter (or upper 1/3 to 1/2 internal sphincter), the patient's distal incision margin (i.e. anal margin) can be extended by 2.2 cm, thus the tumor can be eradicated without the need to excavate the anus, and at the same time, as long as the patient has not yet developed defecation disorder before surgery, the function of the anus can be preserved after functional exercise after surgery. After a detailed preoperative evaluation of Ms. Jin, her tumor local infiltration was confined to the rectal wall and she had not yet developed defecation dysfunction, so she could undergo ISR surgery. The surgical plan designed for her was a combined TEM (endoscopic microsurgery of the anus) and laparoscopic radical rectal cancer surgery, in which the surgical specimen was removed through the natural orifice of the anus, completely avoiding the abdominal incision and realizing a real minimally invasive incisionless radical rectal cancer surgery. On the third day after surgery, Ms. Jin began to eat liquid food after her anus was exhausted, and before discharge, the nurse instructed her to perform functional exercises for the anal sphincter, which is the only feasible method to preserve the anus for ultra-low rectal cancer invading the internal sphincter. The doctor formulated a chemotherapy plan for Ms. Kim, and she was confident about her future life. The tumor, routinely performed by combined transabdominal perineal resection, requires excision of the anus, and the patient can only defecate and vent through the fistula in the abdomen after surgery, which seriously affects the quality of life.