Clinical manifestations and treatment of fecal fistula

Fecal fistula is a sore that occurs in the rectum. It causes discomfort and in severe cases, it may cause pus discharge and other problems. Patients with fecal fistula should have sufficient understanding of the disease so as to cooperate with doctors to receive treatment. Currently, the main treatment for fecal fistula is surgery, and the recovery rate of patients with fecal fistula after surgery is extremely high.

1. Clinical manifestations of fecal fistula

It ranges from mild to significant fecal overload. When the fistula is small or the anus is narrow or imperforate, it manifests as chronic incomplete intestinal obstruction. A few days or even months after birth or after 2 to 3 years old, children may have difficulty defecating and stubborn constipation, sometimes requiring enema or laxatives to defecate. If the fistula is large, there will be no obstruction symptoms but there will be abnormal defecation position, pain during defecation and deformed stool.

Diagnosis of fecal fistula

Fecal fistula can generally be diagnosed based on clinical manifestations and symptoms of the original disease, but the location of the fistula must be accurately located in order to determine the treatment plan. The location of the fistula should be determined by inserting a probe into the fistula to explore its course; or by observing under a colonoscope; and by performing fistula angiography when necessary to determine the location of the fistula. Place gauze in the vagina and inject 10 cm of methylene blue into the rectum. After a few minutes, remove the gauze and observe whether it is stained blue to determine whether there is a vaginal fistula.

Treatment of fecal fistula

All types of congenital anorectal malformations require surgical treatment. However, depending on the type of deformity, the size of the fistula, etc., different operation times and methods may be required. The goal of surgery is to restore normal bowel control. Fecal fistula is difficult to operate on due to its complex causes, numerous types, high postoperative infection and recurrence rate. In order to achieve a successful operation, the choice of surgical procedure is extremely important.

For patients with congenital anal malformation and fecal fistula, attention should be paid to: ① surgical method and operation method; ② whether the end of the rectum is fully freed; ③ avoiding serious infection; ④ fully loosening the end of the rectal mucosa to achieve tension-free suture.

Anal atresia combined with low-positioned rectovaginal fossa navicularis fistula: For cases with a very small fistula and difficulty defecating after birth, a stoma can be created in the neonatal period. If the fistula opening is very close to the vaginal opening, anal plasty should be performed after the child is 4 to 5 years old. If the vaginal fistula is large and stool discharge is unobstructed, there is no need for early surgery. It is more appropriate to have surgery when the child is 3 to 5 years old.

For acquired fecal fistula, especially iatrogenic fecal fistula, the timing of surgery should be chosen carefully and surgery should not be performed immediately because of the patient's urgent request. Surgery should be performed 3 months after injury or repair, after all inflammation has subsided and scars have softened. If the fistula is large, wait 6 months. At the same time, all inflammations must be properly drained.

Surgical method

1. Fistula excision and layered suture

After the fistula is removed, it is sutured in layers and can be repaired through the vagina or rectum. The advantages are simple surgery and easy operation. The disadvantage is the high recurrence rate. Due to the tension during suturing, the rectal or vaginal tissue is separated unevenly, so the mucosal muscle flap must have sufficient blood supply.

2. Rectal mobile flap repair

After satisfactory anesthesia, the patient is placed in the prone position, the internal and external openings are first explored, a probe is inserted into the fistula tract, and a "U"-shaped incision is used for the rectal mucosal flap. The length-to-width ratio of the flap cannot be greater than 2:1, and adequate blood supply must be ensured. 1:20000 epinephrine was injected submucosally to reduce bleeding. The internal sphincter was divided and sutured in the midline. The mucosal tissue with a width of about 0.3 cm is excised around the fistula to form a wound. Then the movable flap is pulled down to cover the internal wound. Intermittent sutures are performed with 2-0 or 3-0 intestinal sutures to restore the normal anatomical relationship between the mucosa and the skin. The vaginal wound is not sutured and is used for drainage.

3. Sacro-abdominal perineal surgery

Since the levator ani muscle of a newborn is only about 1.5 cm away from the anus, it is very easy to damage the puborectal ring when the perineum is separated from the rectum. The sacrococcygeal incision can clearly identify the puborectal ring, free the rectum, and easily separate and remove fistulas with higher openings. The surgery is suitable for infants over 6 months old. The longitudinal incision of the sacral skin is about 3 to 5 cm long, and the sacral cartilage is cut transversely to expose the blind end of the rectum; a longitudinal incision is made along the blind end of the rectum to find the fistula in the intestinal cavity, separate the fistula, cut it off and then suture it. The rectum is mobilized until it can relax and descend to the level of the anal fossa skin. Make an X-shaped incision in the skin of the anal fossa to expose the external sphincter, and slowly pull the rectum from the middle of the puborectal ring to the anus. Be careful not to twist the intestinal segment and avoid forceful expansion of the fingers inside the intestinal ring. The rectal wall and the subcutaneous tissue of the anus are sutured with several stitches of silk thread, and the full thickness of the rectum and the anal skin are sutured intermittently with 3-0 catgut or silk thread. Close the sacrococcygeal wounds one by one.