What Is Imperforate Anus?

Medically Reviewed by Amita Shroff, MD on May 20, 2023
Written by WebMD Editorial Contributors
4 min read

Imperforate anus is a health condition that comes about while a baby is still growing in the womb. While there's no way to prevent imperforate anus from happening, there are surgical treatment options available to correct it. 

Imperforate anus, or anorectal malformation, occurs when the anal opening and rectum do not develop correctly. It is a congenital problem, a defect that occurs before a baby is born, and it prevents the baby from passing stool normally. A baby with an imperforate anus may have an anal opening that is:‌

  • Too small for stool to pass
  • In the wrong location
  • Completely missing, causing stool to pass into the pelvic area, vagina, or bladder instead

In some cases, the rectum, urinary tract, and reproductive tract all connect into one single channel. In most if not all cases, there's a strong risk of infection for a child with this condition.

Signs of imperforate anus. When your baby is born, your doctor will check for imperforate anus. The first step is to see if the anus is open and in the correct position on the body. The second step is to monitor the baby's stools in the first 48 hours. Your doctor and nurses will ask you to write down when your baby has wet and dirty diapers, how much stool there is, and what the stool looks like.

If your baby is passing stool as expected, imperforate anus may not be a concern. But if your baby doesn’t poop as much as expected, your doctor may want to have these tests done:

  • An X-ray of your baby’s belly to check the size of the rectum and the formation of the lower backbone
  • An ultrasound to check the urinary tract and kidneys for excess fluids
  • An ultrasound to check the spinal cord for nerve issues that might cause incontinence
  • An echocardiogram to look for possible heart defects‌

Your doctor looks for other birth defects because 50% of babies with imperforate anus also have another deformation.

Imperforate anus may lead not only to various infections but also to severe constipation. You'll want to have it diagnosed and addressed quickly before it causes additional health issues for your baby.‌

If the nerves that tell your baby to pass a stool are missing or damaged, specialized care may be needed. This is especially true when it is time to potty train your child, because they may not have the ability to know when they need to poop.

Surgery is almost always the required treatment for imperforate anus. Your doctor will decide what type of surgery to do based on how severe the situation is. They will also look at your baby’s overall health and whether they need to address other conditions or deformities.

If the condition is minor, like a narrow or low opening, one surgery may correct the issue. More complicated conditions may require multiple surgeries.

For severe imperforate anus, your baby may need a colostomy bag until all surgeries are complete. Surgery for complicated cases typically realigns the large intestine to remove waste from the body.

While your child may need long-term care to manage the condition, most children learn to control their bowel movements by themselves. But even after surgery, your child may struggle with constipation. You can help by offering a proper diet with correct nutrition, plenty of fiber, and hydration.

If you have concerns as your child grows, talk to your doctor. They can help with physical therapy, medication recommendations, and at-home-management tools.‌

Sadly, half of the babies with imperforate anus may suffer from one or more of these problems also:

  • Spinal defects, where vertebrae in the spine are out of alignment, too tight, or damaged. 
  • For girls, defects in the vagina, uterus, and ovaries.
  • Heart defects. 
  • Tracheal-esophageal fistula. The trachea, which carries air to your lungs, and the esophagus, which carries food to your stomach, should be two separate tubes. In some cases, the two are connected.
  • Abnormalities of the kidneys, bladder, and urinary tract, making it difficult or impossible to pass urine.
  • Malformed hands, arms, feet, and legs.

Some conditions appear on an ultrasound while you’re still pregnant. When they do, it gives doctors a chance to gather the needed staff and expert input in order to plan care for after your baby’s birth. 

Once your baby is born, you should discuss your particular concerns with your doctor, too, and ask about possible testing. Your doctor likely will refer you to specialists for more in-depth analyses of your baby's imperforate anus and added conditions.