Pediatric Anorectal Malformations or Imperforate Anus

Anorectal malformations, also known as imperforate anus, are congenital defects that occur in developing babies early on in pregnancy. A pediatric anorectal malformation can range from mild to complex and develop differently in males and females. Treatment and prognosis will vary depending on the type and severity of the condition.

These malformations occur when the baby’s anal opening, rectum and associated nerves that signal the body that it’s time to go to the bathroom do not develop properly. As a result, the patient is unable to have normal bowel movements, which can lead to a host of other health problems. 

Types of anorectal malformations may include:

• An anal opening that is too small or is in the wrong location leads to bowel pain and/or severe constipation.
• The absence of an anal opening as a result of the large intestine and rectum entering other areas of the pelvis can lead to dangerous health problems, including:
• Bowel obstruction (a condition that causes stool to be trapped in the body)
• Chronic infections resulting from stool entering the bladder or vagina
• The absence of the anal opening causes a cloacal deformity (when the rectum, vagina and urologic structures form one channel rather than three separate openings, leading to chronic infections and kidney injury).

Symptoms of anorectal malformation may include:

• A missing anal opening or incorrectly placed anus at birth
• Stomach swelling
• Not having bowel movements

The key to receiving the best possible outcome is an accurate diagnosis. We offer the latest, advanced tests and tools to diagnose anorectal malformations. 

If your child is being evaluated for an imperforate anus, the following diagnostic tests may be performed:

• Abdominal ultrasound: to examine the urinary tract, kidneys and to look for fluid build up
• Echocardiogram: to detect possible heart defects
• Spinal ultrasound: to evaluate for spine abnormalities (such as a tethered cord) which may cause certain neurological problems
• X-rays: to examine the pelvic and stomach area

A 3D cloacagram may be used for children born with cloaca to help define the anatomy and plan for surgery:

Most babies with anorectal malformation will need one or more specialized surgeries to correct the problem. Our highly experienced colorectal surgeons are trained in the latest surgical approaches for all types of anorectal malformations including implementing leading-edge, minimally invasive techniques. 

Surgical repair for imperforate anus includes:

Colostomy

A colostomy is a surgical procedure that creates an opening for the colon, or large intestine to excrete waste in a small bag located outside of the body. Most babies born with an anorectal malformation will need a temporary colostomy within the first few days of life. The colostomy will ensure the baby can properly pass stool, helps to normalize digestion and greatly reduces the risk of infection.

Posterior Sagittal Anorectoplasty (PSARP)

Anorectal reconstructive surgery, also known as posterior sagittal anorectoplasty (PSARP), is performed to connect the rectum to the anal opening as well as close any abnormal openings that may interfere with the ability to have a normal bowel movement.  In cases where there is an absence of an anal opening, your surgeon will create a new one. 

The majority of PSARP procedures are performed when a baby is between one and six months old. The type of PSARP performed will depend on the position of the rectum and anus (whether it is low or high), how well the sphincter muscles work, and if there are any abnormal openings (called fistulas) that need to be repaired. For appropriate cases, pediatric surgeons at Children’s National Hospital use minimally invasive, laparoscopic techniques to help reduce the damage to surrounding structures and minimize pain post-surgery. 

Colostomy Closure

Your child’s colostomy will remain in place for approximately eight weeks following the reconstructive surgery to allow the rectum and anal opening to heal before coming in contact with any waste. When your child is ready and completely healed, the colostomy will be surgically closed. Within several days, they will begin passing stools on their own through the anus. At first, stools will be loose and occur frequently. To protect your child’s skin from diaper rash and irritation, safe topical treatments should be applied. As your child continues to heal, their stools will normalize, becoming firmer and less frequent.

Recovery from anorectal reconstructive surgery will typically require two to four days in the hospital. For several months after surgery, anal dilations may need to be performed to help stretch the anus to the appropriate size for your child’s anatomy and age. Although surgery restores some function, the nerves and sphincter muscles your child relies on to let them know they need to go to the bathroom may be weak. After surgery, some children continue to experience difficulty with constipation, soiling themselves and have problems potty training, but these can all be successfully managed using a bowel management program. If necessary, this program will help restore your child to maximum function and strengthen their muscle after surgery. To combat constipation, a combination of a healthy diet, plenty of fiber and laxatives (if needed) should be maintained. You should speak with your surgeon about what recovery will mean for your child.