Rectovaginal fistula

　　Rectovaginal fistula is the communication between the rectum and vagina. If the fistula opening is large and defecation is not obstructed, this fistula may be asymptomatic. Rectovaginal fistula mostly occurs in congenital anal-rectal malformations. The clinical manifestations of rectovaginal fistula range from mild fecal incontinence to significant fecal incontinence. When the fistula opening is small, or the anal canal is narrow or atresia, it is manifested as chronic incomplete intestinal obstruction. Children may have difficulty defecating a few days or even months after birth, or after 2 to 3 years old, with stubborn constipation, sometimes requiring enema or laxatives to defecate. There are many causes of rectovaginal fistula, such as:

　　1. Congenital malformation.

　　2. Delivery injury, the most common, including dystocia and obstetric surgery.

　　3. Gynecological surgery injury, including abdominal or vaginal pelvic gynecological surgery.

　　4. Inflammatory bowel disease.

　　5. Chemical corrosion or foreign bodies.

　　6. Cancer erosion or radiation therapy after treatment.

　　7. Other penetrating or closed injuries, such as injuries from falling astride or rape, can also form this type of fistula.

　　Among many causes, third-degree perineal laceration, obstetric surgery such as perineal incision, especially perineal rectal incision, are prone to develop rectovaginal fistula. If these injuries are not detected in time, or if they are not repaired in time or if infection occurs after repair, rectovaginal fistula and rectal or vaginal surgery will eventually occur, especially if the fistula is close to the dentate line.

　　The length of the segment where the female rectum and the posterior vaginal wall are adjacent is about 9cm, so any part of this rectovaginal septum can develop rectovaginal fistula in cases of trauma, inflammation, and other lesions. It is the most common type of fecal fistula in gynecological and obstetric clinical practice and can cause other complications.

　　1. Vaginitis

　　The vaginal orifice is closed, the anterior and posterior vaginal walls are tightly adherent, and the vaginal epithelial cells proliferate and keratinize under the influence of estrogen. The vaginal pH is maintained at 4-5, which inhibits the proliferation of alkaliphilic pathogens such as anaerobic bacteria. When the natural defense function of the vagina is destroyed, pathogens are easy to invade, leading to vaginal inflammation.

　　2. Intestinal obstruction

　　Obstruction of the passage of intestinal contents, simply put, is the unobstructed condition of the intestines. Here, the intestines usually refer to the small intestine (jejunum, ileum) and the colon (ascending colon, transverse colon, descending colon, sigmoid colon). Acute intestinal obstruction is one of the most common surgical acute abdominal conditions, which can be frequently encountered in the emergency room. Due to various reasons, the mortality rate is still relatively high, about 5%-10%; if intestinal strangulation occurs, the mortality rate can rise to 10%-20%.

　　The clinical symptoms of rectovaginal fistula vary from mild fecal incontinence to significant fecal incontinence. When the fistula is small or there is anal stenosis or anal atresia, it manifests as chronic incomplete intestinal obstruction. In the days after birth, even a few months or 2-3 years later, children may have difficulty defecating, with stubborn constipation, and sometimes enemas or laxatives are needed to defecate. If the fistula is large, there are no obstruction symptoms but there are abnormal defecation location, defecation pain, and feces deformation symptoms.

　　The degree of fecal incontinence in patients with rectovaginal fistula varies from mild to significant. When the fistula is small or there is anal stenosis or anal atresia, it manifests as chronic incomplete intestinal obstruction, which is very painful in life. Then, what are the ways to prevent it?

　　1. For rectovaginal fistula caused by childbirth, pay attention to protecting the perineum during delivery.

　　2. There are no effective preventive measures for congenital anal-rectal malformations.

　　Rectovaginal fistula can generally be diagnosed according to clinical manifestations and symptoms of the original disease, but the location of the fistula needs to be accurately located to facilitate the determination of the treatment plan.

　　The position of the fistula should be explored with a probe; or observed under rectoscopy; if necessary, perform fistula angiography to determine the position of the fistula. Vaginal palpation can sometimes feel the fistula on the posterior wall of the vagina; or use a vaginal speculum for examination, which can be seen under the exposure of the vaginal speculum, a small fistula, or a small bright red granulation tissue can be seen; place gauze in the vagina, inject 10cm of methylene blue into the rectum, and then remove the gauze after several minutes to observe whether it is stained blue to determine whether there is a vaginal fistula.

　　Patients with rectal perineal fistula have higher dietary requirements after surgery due to the surgical site being in the rectal perineal area. After discharge, it is advisable to eat easily digestible, nutritious, and balanced diet. Pay attention to regular living and dietary habits, and pay attention to dietary hygiene. Avoid eating raw, cold, hard, fried, and salted foods, and develop a good habit of regular defecation.

　　Example of a daily diet plan:

　　Breakfast: Millet porridge (50g of millet), corn cake (50g of corn flour), mixed cabbage (50g of cabbage).

　　Supplementary meal: 1 apple (200g of apple).

　　Lunch: Buns (50g of eggs, 100g of cabbage, 100g of celery, 100g of flour), soup (50g of tomatoes, 50g of cucumber, 10g of starch).

　　Supplementary meal: 1 small bowl of lotus root starch (30g of lotus root starch, 10g of sugar), 2 pieces of vegetable biscuits (20g of flour).

　　晚餐：大米粥50克(大米50克)，馒头(面粉50克)，拌豆腐(北豆腐100克)，蒸蒜拌茄泥(茄子100克)。

　　Dinner: 50 grams of rice porridge (50 grams of rice), steamed bun (50 grams of flour), mixed tofu (100 grams of northern tofu), steamed garlic mixed with eggplant puree (100 grams of eggplant).

　　The general method of Western medicine for treating rectovaginal fistula

　　Surgical treatment is suitable for children over 6 months old. The longitudinal incision of the sacral tail skin is 3-5 cm long, and the sacral tail cartilage is transversely incised to expose the rectal blind end; along the longitudinal incision of the rectal blind end, the fistula orifice is found in the intestinal cavity, separated, cut, and sutured. The rectum is freed to be able to relax and descend to the skin level of the anal fossa. The skin of the anal fossa is made into an X-shaped incision, exposing the external sphincter, and the rectum is slowly pulled through the puborectalis ring to the anus, paying attention not to twist the intestinal segment and avoiding strong expansion of the finger in the intestinal ring. Several sutures are made with silk thread between the rectal wall and the subcutaneous tissue of the anus, and the full thickness of the rectum and the anal skin are sutured with 3-0 intestinal suture or silk thread in an interrupted manner. Close the wound at the sacral tail in turn.

　　In addition, high rectal atresia and rectovaginal fistula can also be treated with abdominal perineal analoplasty, rectovaginal fistula repair surgery, and colostomy in neonates, but due to actual conditions, the mortality rate of surgery is high and it is not easy for parents to accept it. The main surgical complications of all high fistulas are infection and fistula recurrence, and the difficulty of reoperation is relatively large. Treatment plans should be formulated for each specific case according to its condition and actual conditions, and appropriate surgical methods should be chosen.

　　For patients with congenital rectovaginal fistula, treatment should be based on the etiology. For those caused by inflammation, active treatment of enteritis should be carried out after controlling the inflammation, and the choice of repair, intestinal resection, and colostomy should be determined according to the condition. For patients with rectovaginal fistula caused by obstetric surgery and trauma, repair surgery through the rectum or vagina should be performed after controlling the inflammation. The edges of the rectum and vagina are incised and separated, and the rectal wall is closed in a transverse manner to form an inversion. The submucosal tissue of the vagina is sutured longitudinally, and the vaginal mucosa is closed transversely.