Postoperative rectovaginal fistula after low rectal cancer is a relatively rare complication with a clinical incidence of less than 1%, but it is difficult to manage clinically and is often prone to recurrence, which is a very difficult complication to deal with, and there is no clinical guideline with a high level of evidence to guide the treatment of this disease. The author, based on his clinical experience and the literature, summarizes several experiences for reference. 1. Careful intraoperative separation and operation to prevent the occurrence of rectovaginal fistula Injury to the operation and anastomosis to the vagina during low rectal cancer surgery is an important cause of rectovaginal fistula, so minimizing intraoperative injury is an important aspect. First, careful separation should be performed during surgery to avoid damage to the vaginal wall, and during total mesenteric resection, the sphincter should be fully exposed on the anterior side of the rectum in addition to the posterior side and both sides to achieve adequate free rectum; second, when closing the rectal stump with a closure device or cutting the distal rectum with a linear cutter under laparoscopy, an assistant can be asked to place a finger in the vagina before striking to do Third, when performing anastomosis, the assistant also needs to lift the vagina to reduce the possibility of injury, and if the lift is not obvious, the anastomosis can be done from the posterior side of the rectum to avoid partial vaginal involvement in the anastomosis site. Fourth, after surgery, it is best to place a drainage tube in front of the sacrum to reduce postoperative pelvic fluid and to prevent pelvic infection due to Among the 16 cases of rectovaginal fistula reported by Kosugi et al, 6 cases were due to anastomotic leakage, which formed local abscesses that compressed and penetrated the posterior vaginal wall, forming rectovaginal fistula. Fifth, if total mesenteric resection is performed, unless the anastomosis is very definite, prophylactic ileostomy is usually needed to reduce the occurrence of anastomotic fistula and the formation of pelvic abscess and prevent the occurrence of rectovaginal fistula. 2. If any vaginal injury is found after the anastomosis, the anastomosis needs to be removed and the coloanal anastomosis reperformed After the anastomosis is performed, the anastomotic circle should be carefully checked for vaginal wall tissues. After vaginal preparation, the author applies gentian violet on the posterior vaginal wall before performing low rectal surgery, which can be easily detected once the vaginal wall is mistakenly injured due to the anastomosis or the closure during the operation. Alternatively, a vaginal examination can be performed and if there is a vaginal injury, it can be evident that there appears to be adhesions between the rectum and the vagina, which is something to be aware of and consider a possible vaginal injury. If a vaginal injury is found, the effect of intraoperative repair alone is not very satisfactory and requires continued freeing and removal of the anastomosis. If the rectal stump can be cut off with closure in the abdominal cavity with a closure device and then an anastomosis is performed, the anal function may be more satisfactory after the anastomosis, and if the anastomosis cannot be completed in the abdominal cavity, a rectoanal anastomosis with anal tow out can be performed. After completing this anastomosis, an ileostomy or Transverse colostomy, and the time of stoma return is usually chosen to be performed after 3-6 months postoperatively. After proper treatment, the possibility of postoperative rectovaginal fistula is very small. 3.If rectovaginal fistula occurs after surgery, you need to choose interposition of labia majora fasciocutaneous flap or interposition of thin femoral muscle If no rectal injury is found during surgery and rectovaginal fistula occurs after surgery, we usually use transposition of popular stoma and then wait for it to heal by itself, in fact, the self-healing rate of rectovaginal fistula is low after simply performing transposition of stoma, Kosugi et al. reported that rectovaginal fistula after rectal cancer surgery only by performing transposition of stoma. Kosugi et al. reported a self-healing rate of only 42.9% for rectovaginal fistulas after rectal cancer with only a diverting stoma, and all of these patients who healed on their own were patients with anastomotic leaks complicated by abscesses resulting in rectovaginal fistulas, while those patients who had damage to the vaginal wall did not benefit from the stoma. Those patients with simple rectovaginal fistulas, when the etiology is clearly an anastomotic fistula complicated by an abscess, can be treated non-operatively and observed first and do not require a diversionary stoma, whereas those patients with vaginal wall injury, partial vaginal wall resection or unknown etiology should have a diversionary stoma requiring elective surgical repair. The key to repairing a rectovaginal fistula is reconstruction of the anterior rectal wall and restoration of the “high pressure zone” in the rectal and anal canal areas. Repair alone, even in the presence of a stoma, is very unlikely to be successful due to surgical scars around the anastomosis, chronic inflammation, and limited tissue available for repair, resulting in excessive tension and insufficient blood supply to the tissue. Nakagoe et al. reported four cases of successful perineal repair of rectovaginal fistula after surgery for low rectal cancer, but the success rate of perineal repair of rectovaginal fistula is not high. For this rectovaginal fistula, the labia majora fasciocutaneous flap or thin femoral muscle interposition surgery can be chosen, but the labia majora fasciocutaneous flap is difficult to perform this surgery if the anastomosis is positioned 2 cm above the dentate line due to less tissue and limited flap length, and as for the success rate of the labia majora muscle transfer surgery, reports are inconsistent and generally considered to be 67-94%. With interposition of the femoralis muscle, the femoralis muscle is longer and has more tissue to repair rectovaginal fistula with a higher anastomosis, but the success rate is less reported and is generally considered to be around 80%. Although the failure rate after interposition surgery is around 30-50%, it can be an option because it is easily accepted by the patient via perineal surgery. 4.If interposition surgery is used and fails, transabdominal fistulotomy and coloanal drag-out anastomosis is needed If interposition surgery is used and fails, transabdominal fistulotomy and coloanal drag-out anastomosis is needed, which is traumatic, difficult, and has many surgical complications, but the postoperative results are better and the success rate can reach more than 90%, and Rex et al. even reported that the success rate of reanastomosis can reach 100%. This procedure is often used as a last resort for rectovaginal fistula treatment, and if it is still unsuccessful, a permanent ileostomy is required. Although rectovaginal fistula is a relatively uncommon postoperative complication of low rectal cancer, once it occurs, it is difficult to manage and affects the patient’s recovery time after surgery. Prevention of rectovaginal fistula is more important than treatment, and it is especially important to operate carefully during surgery, so that rectovaginal fistula can be detected and treated intraoperatively.