Imperforate anus repair is surgery to correct a birth defect involving the rectum and anus.

An imperforate anus defect prevents most or all stool from passing out of the rectum. 

Anorectal malformation repair; Perineal anoplasty; Anorectal anomaly; Anorectal plasty

How this surgery is performed depends on the type of imperforate anus. The procedures are done under general anesthesia, which means the infant is asleep and feels no pain during the procedure.

For mild imperforate anus defects:

• The first step involves enlarging the opening where the stool drains, so stool can pass more easily.
• Surgery involves closing any small tube-like openings (fistulas), creating an anal opening, and putting the rectal pouch into the anal opening. This is called an anoplasty.
• The child must often take stool softeners for weeks to months.

Two surgeries are often needed for more severe imperforate anus defects:

• The surgeon will create an opening in the skin and muscle of the abdominal wall and attach the end of the large intestine to the opening. Stools will drain into a bag attached to the abdomen. This is called a colostomy.
• The baby is often allowed to grow for 3 - 6 months.
• For the second procedure, the surgeon may make a cut in the abdomen to detach and move the colon to a new position. A cut is made in the anal area to pull the rectal pouch down into place and create an anal opening.
• The colostomy will likely be left in place for 2 - 3 more months.

A major challenge for these repairs is creating an anal opening using nearby muscles and nerves so that the child can move the bowels normally and does not suffer from incontinence.

The surgery repairs the defect so that stool can move through the rectum.

Risks from any anesthesia include:

• Reactions to medications
• Problems breathing

Risks from any surgery include:

• Bleeding
• Infection

Risk from this procedure include:

• Damage to the urethra (tube that carries urine out of the bladder)
• Damage to the ureter (tube that carries urine from the kidneys to the bladder)
• Hole that develops through the wall of the intestine
• Abnormal connection (fistula) between the anus and vagina or skin
• Narrowed opening of the anus
• Long-term problems with bowel movements because of damage to the nerves and muscles to the colon and rectum (may be constipation or incontinence)
• Temporary functional paralysis of the bowel (paralytic ileus)

The infant may be able to go home later the same day if a mild defect is repaired. Or, the child may spend several days in the hospital.

The health care provider will use an instrument to stretch (dilate) the new anus to improve muscle tone and prevent narrowing. This stretching must be done for several months. Stool softeners and a high-fiber diet are recommended throughout childhood.

Most defects can be corrected with surgery. Most children with mild defects do very well. However, constipation may be a problem.

Children who have more complex surgeries still usually have control of their bowel movements. However, they often need to follow a bowel program, which includes eating high-fiber foods, taking stool softeners, and sometimes using enemas.

Some children may need more surgery. Most of these children will need to be followed-up closely for life.

Children with imperforate anus may also have other birth defects, including problems with the heart, kidneys, arms or legs, or spine.

Warner BW. Pediatric surgery. In: Townsend CM, Beauchamp RD, Eyers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 71.

Stafford SJ, Klein MD. Anus and rectum. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 336.