Anorectal Malformation | Diagnosis & Treatment

How are anorectal malformations diagnosed?

Your baby's physician will perform a physical examination when your baby is born, and will look at the anus to see if it is open and in the proper position. If the doctor suspects an anorectal malformation, he or she may order diagnostic imaging to get more details on the severity of the problem:

What are the treatment options for anorectal malformations?

The majority of babies with anorectal malformations will need to have surgery to correct the problem. The type and number of operations necessary depends on the type and extent of the abnormality.

Narrow anal passage

Babies who have the type of malformation that causes the anal passage to be narrow may not need an operation. A procedure known as anal dilatation may be done periodically to help stretch the anal muscles so stool can pass through it easily. However, if the anal opening is positioned incorrectly, an operation may be needed to relocate it.

Anal membrane

Babies with this type of malformation will need to have the membrane removed during surgery. Anal dilatations may need to be done afterward to help prevent narrowing of the anal passage.

Lack of rectal-anal connection (with or without a fistula)

These babies may need a series of operations in order to have the malformation repaired.

The first procedure is called a colostomy. In a colostomy, the large intestine is divided into two sections and the ends of intestine are brought through openings in the abdomen. The upper section allows stool to pass through the opening (called a stoma) and then into in a collection bag. The lower section allows mucus that is produced by the intestine to pass into a collection bag. By doing a colostomy, the baby's digestion will not be impaired and she can grow before the time for the next operation. Also, when the next operation is done on the lower section of intestine, there will not be any stool present to infect the area. 
 
The nursing staff and other health care professionals that work with your baby's surgeon can help you learn to take care of the colostomy. Local and national support groups may also be of help to you during this time.

The next operation attaches the rectum to the anus and is usually done within the first few months of a baby's life. The colostomy remains in place for a few months after this operation so the area can heal without being infected by stool. (Even though the rectum and anus are now connected, stool will leave the body through the colostomy until it is closed with surgery.) A few weeks after surgery, parents may start performing anal dilatations to help the baby get ready for the next phase of treatment.

Two to three months later, an operation is done to close the colostomy. The baby is not allowed to eat anything for a few days after surgery while the intestine is healing. 

Several days after surgery, the baby will start passing stools through the rectum. At first, stools will be frequent and loose. Diaper rash and skin irritation can be a problem at this time. Within a few weeks after surgery, the stools become less frequent and more solid, often causing constipation. Your baby's physician may recommend a high fiber diet (including fruits, vegetables, juices, whole-wheat grains and cereals) to help with constipation.

What is the long-term outlook for children with anorectal malformations?

The long-term outlook depends on the type of anorectal malformation. Children who had the type of malformation that involves an anal membrane or a narrow anal passage are usually able to gain good control over their bowel movements after the malformation is repaired. 

Children with more complex anorectal malformations may need to participate in a bowel management program to help them achieve control over their bowel movements and prevent constipation. Our nurses and other health care professionals can help tailor a program to suit your child’s needs.

Your child can begin toilet training at the usual age, which is generally between two and three years old. However, children who have had anorectal malformations repaired may be slower than others to gain bowel control. Some children may not be able to gain good control over their bowel movements, while others may be chronically constipated, depending on the type of malformation and its repair.

Sometimes these children also have difficulty controlling urine and do not properly toilet train, remain wet after training or develop repeated urinary infection. Imaging of the urinary tract with a renal ultrasound and a voiding cystourethrogram (a special bladder X-ray) may help clarify the cause of these problems.