Traditionally, in order to ensure radical treatment, for ultra-low rectal cancer within 5 cm from the lower edge of the tumor to the anus, it is considered that combined abdominal and perineal resection (APR), that is, Miles surgery, is the standard treatment [
1]. However, permanent stoma also brings more stoma-related complications [
2] and urogenital dysfunction [
3,
4] to patients. In addition, long-term nursing care of stoma [
5], persistent mental pressure of stoma on patient’s image change, and other factors seriously affect the quality of life [
6] and the realization of social function [
7] of patients after Miles, making patients’ attitude toward the postoperative treatment more negative. Therefore, many patients with rectal cancer have a strong sense of rejection of stoma before surgery [
8]. With the development of preoperative neoadjuvant radiotherapy and chemotherapy [
9,
10] and laparoscopic techniques [
11], as well as the confirmation of the principle of total mesorectal excision (TME) [
12‐
15] and the understanding of the concept of circumferential margin [
16], the prognosis of anus-conserving surgery has been greatly improved. There are also more and more related research and application of anus-conserving surgery. However, there is still controversy about whether anus-preserving surgery should be performed for ultra-low rectal cancer. The focus is whether the radical resection of the tumors and a good anal function can be guaranteed after the resection of all or part of the internal sphincter [
17].
The key to the radical treatment of anus-preserving surgery is to ensure the safety of distal incision margin, which has been a research hot spot for a long time [
18‐
21]. Many related literatures have confirmed that 1 cm distal resection margin does not affect the oncological safety of rectal cancer [
21,
22]. These studies and findings provide a theoretical basis for expanding the indications of anus-preserving surgery for ultra-low rectal cancer. However, there are few studies on anal function and quality of life after anus-preserving surgery, and most of them focus on patients undergoing intersphincteric resection (ISR) [
23] and adjuvant radiotherapy and chemotherapy after ISR [
24].
By combining the advantages of traditional Bacon surgery [
25,
26], the modified Parks surgery was used in the Department of Colorectal and Anal Surgery of Xiangya Hospital of Central South University, China, to perform anus-preserving surgery for ultra-low rectal cancer, and the anal function and FIQL of the patients after modified Parks surgery were further studied. The results showed that the modified Parks surgery could achieve a good anal function and FIQL for patients with ultra-low rectal cancer while preserving the anus.