A rectovaginal fistula is a fistula in which the rectum communicates with the vagina, causing gas, secretions or feces to come out of the vagina. It belongs to the category of “yin blowing” and “yin erosion” in Chinese medicine. Rectovaginal fistula is one of the more difficult problems in the treatment of anorectal surgery. There are many treatment methods for rectovaginal fistula, some of which are too complicated, difficult to care for, and expensive to treat, making it difficult for patients to accept. In the past 10 years, we have used trans-perineal repair to treat medium and low rectovaginal fistulas and have obtained better results. From 1996 to 2005, we treated 15 cases of rectovaginal fistulas with transperineal repair, with an average age of 28 years (20-74 years) and a maximum fistula diameter of 75 px; a minimum of 37.5 px; 10 of these cases developed since childhood, but the cause was unknown; one case was an elderly person, due to fecal impaction and injury from finger-guiding. In the other 4 cases, there were 2 patients with rectal cancer and 1 patient with cervical cancer after surgery and radiotherapy. The average number of repairs before consultation was 3. All patients underwent preoperative rectal examination, proctoscopy, colonography and histopathological examination of the fistula margin. Postoperative outpatient or telephone follow-up was performed. 2. Indications: For simple medium and low rectovaginal fistula. 3. Contraindications: acute inflammation of the local or storage pouch; rectovaginal fistula caused by radiotherapy, neoplastic or rectal Crohn’s disease. 4. Method: Transperineal repair of rectovaginal fistula. (1) Preoperative routine bowel preparation (same as for rectal cancer), continuous epidural anesthesia, truncated position, routine disinfection of the towel, and vaginal-rectal placement of iodine gauze three times, each time resting for 3 minutes. ②1% lidocaine or saline with paricalcitonin in a 1:5000 solution was used to infiltrate around the fistula and submucosa of the rectovaginal diaphragm to reduce bleeding. ③A curved incision is made with a knife between the anus and the anterior pubis, and a sharp subcutaneous separation is made between the rectum and the vagina up to the rectovaginal fistula and all epithelialized canal wall tissue is removed. ④The rectal defect was closed first with interrupted sutures of No. 0 silk thread followed by interrupted internal sutures. ⑤ The levator muscle was reinforced with interrupted sutures of No. 1 silk. (6) The posterior vaginal wall is interrupted with 3-0 EthiconVicryl absorbable sutures. (vii) If there is a storage bag, the wall is peeled off and the lumen is closed with full sutures. ⑧After placing a skin piece between the rectovagina and another poke to drain and fix it, iodophor gauze is applied externally to the perineal wound 3 to 5 times and set aside for 3 minutes each time, and then the perineal wound is closed with interrupted sutures of No. 4 silk thread and covered with gauze to fix it externally. ⑨ Dry gauze was placed in the vagina and a rubber tube connected to a sterile bag was placed in the rectum for drainage, and attention was paid to fixation. After surgery, sitz baths were given twice a day after decoction with Chinese herbal medicine to remove toxins, activate blood circulation, and relieve swelling and pain; intravaginal gauze was changed 1 to 2 times to keep it as dry as possible; intrarectal chlorhexidine hemorrhoid suppositories were placed 1 capsule daily; fasting was given for 5 to 7 days, and supportive therapy and effective antibiotics were given; stool control was given for 7 to 10 days; the skin piece was usually withdrawn after 24 hours, and the rubber tube placed in the rectum was usually withdrawn after 3 to 5 days. The perineal wound was changed daily until it was healed, and the stitches were removed in 1 week. 5.Results All patients in this group healed at stage I except those with tumor and radiation therapy and Crohn’s disease. The average hospital stay was 9 days (7-13 days), and the average follow-up was 24 months (12-30 months). During the follow-up period, no recurrence cases were found, and the success rate was 73%. The postoperative anal function of the healed patients in this group was evaluated according to the Parks anal incontinence grading system, and no anal incontinence occurred. The satisfaction rate of the healed patients after surgery was 100% [5]. There was a significant improvement in the postoperative gastrointestinal quality of life index [6]. II. Discussion Rectovaginal fistula has been estimated abroad to account for less than 5% of anal fistulas. The pathogenic factors are both congenital and acquired. Congenital factors are mostly due to anorectal insufficiency and abnormal opening of the rectum to the vagina, and congenital rectovaginal fistula has been reported in about 12% of cases. (1) infections (Crohn’s disease, perianal abscess, Bartholin’s gland infection, diverticulitis, lymphogranuloma venereum, HIV ulcer, tuberculosis, etc.); (2) trauma (11-20% of rectovaginal fistulas due to birth injuries are reported in the literature, with lateralization or tearing of the perineum during delivery being the most common factor leading to rectovaginal fistula, followed by violence and rough intercourse, trauma, etc.); and (3) tumors. (trauma, etc.); ③ tumor infiltration (both rectal and gynecological); ④ complications during treatment such as hysterectomy, low anterior resection, anorectal surgery and pelvic radiation therapy. In terms of diagnosis the presence of a fistula should be suspected whenever gas or stool is expelled from the vagina. ① Determine the cause: a detailed history can assist in finding the cause and the patient’s bowel control status needs to be documented. The presence of a fistula can be determined by placing a cotton plug in the vagina and injecting 1 ml of methylene glycol plus 39 ml of 1% hydrogen peroxide solution into the rectum, then removing the plug and observing the staining; vaginography can be helpful in detecting high fistulas. (3) Defecography can determine the location of large fistulas and the function of the anal sphincter; (4) Sphincter examination should be a necessary step in the diagnosis of every rectovaginal fistula patient, especially in cases of rectovaginal fistula due to birth injury, where fecal incontinence may be caused by sphincter injury. Furthermore, the symptoms of fecal incontinence can be masked by the fistula. Therefore, physical examination and anorectal physiologic examination (including endorectal ultrasound, rectal manometry, and pubic nerve potentials) are important to reveal hidden injuries and to develop a surgical repair plan. ⑤ Proctoscopy not only identifies rectovaginal fistulas but also allows visualization of the rectal mucosa. Biopsies of the mucosa at the edge of the fistula, both with and without lesions, are performed to determine the cause of the rectovaginal fistula. Depending on the cause, size and location of the fistula, rectovaginal fistulas are classified as low or high, simple or complex. Low rectovaginal fistulas have a rectal opening at or slightly above the dentate line and a vaginal opening in the labial ligament, whereas high fistulas have a vaginal opening near or behind the cervix. Intermediate fistulas are intermediate between low and high fistulas. Simple fistulas are those that are low and caused by trauma or infection; complex fistulas are those that are high, large in diameter, caused by radiation therapy, tumors, inflammatory bowel disease, or recurrent fistulas. There are many surgical approaches for the treatment of low to moderate simple rectovaginal fistulas including transanal repair, transvaginal repair, transperineal repair, transsphincteric repair (York and Mason), transanal flap repair, transabdominal repair, and tissue grafting and patching. The general opinion is that rectovaginal fistulas should not be treated by simple fistulotomy or incision; incision of the perineum can cause some degree of anal incontinence; many surgeons and all gynecologists prefer transvaginal repair for rectovaginal fistulas. However, because of the high pressure area on the rectal side, if the opening of the fistula in the rectum is not completely closed, failure is inevitable no matter how carefully the operation is performed in the vagina; trans-sphincteric repair, trans-anal flap repair, trans-abdominal repair, and tissue grafting and patching are difficult to perform, require high conditions, have many complications, cost more, and are less acceptable to patients, especially those in rural areas. Based on our clinical experience over the years, we believe that: ① trans-perineal repair for rectovaginal fistula is less demanding in terms of infrastructure, less traumatic, faster recovery, less expensive, and more suitable for promotion in rural primary care hospitals. ②Through perineal repair, the levator muscle can be pulled together, which reduces local tension and improves local blood circulation, thus improving the healing ability of the repaired wound. ③No need to cut the sphincter, avoiding locking deformity and anal incontinence, and no need to make a protective stoma. ④Transconjunctival repair can repair the defective sphincter at the same time, reducing the complications caused by multiple incisions. ⑤ Trans-perineal repair can be performed while thoroughly separating the rectal and vaginal fistulae, and at the same time repairing the rectum and vagina separately, eliminating the need to turn the patient during the operation. (6) The rubber tube placed in the rectum after surgery can drain the gas and fluid from the intestine to the outside of the body, thus also reducing the high pressure in the rectum affecting the healing of the repaired wound. However, the success rate after repair is low for rectovaginal fistulas caused by acute inflammation locally or in the storage bag; radiation therapy, neoplastic or rectal Crohn’s disease, and the reasons for this deserve further investigation.