Intestinal Atresia and Stenosis

The small intestine is a very important part of the digestive tract: It's where we absorb most of the nutrients from the food we eat. But sometimes children may not be able to absorb all the nutrients their growing bodies require.

Intestinal atresia means that your child's intestines haven't formed correctly. There may be areas of blockage that prevent nutrients from flowing through the digestive tract, or some sections may not be connected to each other.

With intestinal stenosis, the intestine isn't completely blocked, but the inside space (lumen) has narrowed so much that it's difficult for nutrients to move through. Both intestinal atresia and intestinal stenosis are also sometimes referred to as intestinal obstructions.

Intestinal obstructions can nearly always be removed with surgery, but the procedure carries some risk. During surgery, the surgeon meticulously removes as little of the intestine as absolutely necessary, but sometimes fixing the obstruction means your child is left with not enough small intestine to absorb all the nutrition their growing body needs. This condition is called short bowel syndrome (SBS).

The small intestine (small bowel) varies in length between 10 and 28 feet and is divided into three main sections: the duodenum, jejunum, and ileum. Intestinal obstructions are usually classified according to where in your child's intestine the absence, blockage, or narrowing is found. Obstruction in the duodenum is known as duodenal atresia/stenosis, and obstructions in the jejunum or the ileum are both called jejunoileal atresia/stenosis.

Jejunal obstruction may accompany intestinal malrotation, hernia, or abdominal wall defects that strangle the small intestine, interrupting its blood supply. About half of all infants with duodenal obstruction are born prematurely, and more than 30 percent have Down syndrome. Between 50 and 75 percent have other anomalies, which often affect other parts of the digestive system, the heart, or the kidneys.

If your baby has an intestinal obstruction, it will usually be discovered within a day or two of his birth. You or your child's doctors may notice that your baby:

• Doesn't tolerate feedings
• Is vomiting
• Has an abdomen that looks bloated (distended)

Experts believe that intestinal atresia and stenosis are caused by an inadequate supply of blood to your baby's intestines during fetal development. They appear to run in families, although a specific genetic cause has yet to be discovered.

The first step in treating your child is forming an accurate and complete diagnosis. If doctors suspect an intestinal obstruction after your baby is born, they will run tests to see whether there is an obstruction, and if so, determine its location. These diagnostic tests may include:

• An X-ray or ultrasound of your baby's abdomen
• An upper gastrointestinal (GI) test
• A lower GI test, or barium enema

Doctors may also perform imaging studies of your child's heart and kidneys to check for the anomalies that sometimes accompany intestinal obstructions.

Surgery is often the best option for treating intestinal obstructions. During surgery, the surgeon will make an incision in your baby's abdomen and remove the affected part of the intestine, taking care to leave as much of your baby's healthy intestine in place as possible. Then the surgeon will reconnect your baby's intestines.

If a child doesn't have enough small intestine, the remaining part tries to fix the problem on its own. It puffs up like a balloon, creating more surface area to draw in nutrients. But this has an unfortunate side effect: The wider the intestine, the longer it takes for the body to move nutrients through it. More time in the intestines means more time for the bacteria that would normally be swept promptly along to multiply, increasing your child's chance of infection.

To solve both problems at once, surgeons at Boston Children's developed the serial transverse enteroplasty procedure (STEP). This approach exposes more usable surface area and also creates a narrower space, which keeps food moving through your child's digestive tract at an appropriate pace, carrying bacteria out of the body along with the rest of the body's waste.

After surgery, your baby may receive a special, easily digested formula through an IV, and our team will monitor them carefully to assess how well their intestines are healing. When the time is right, we'll transition your child to fewer IV feedings and more oral or tube feedings, with the goal of weaning them off of IV feedings completely.

At Boston Children's Hospital, we treat children with intestinal atresia and stenosis in our Center for Advanced Intestinal Rehabilitation (CAIR), one of the world's premier programs for treating children with SBS. The center includes a team of experts with decades of experience in caring for children with intestinal problems.

Our clinical care is informed by our research. Our researchers have made major contributions to the field: In 2002, doctors at Boston Children's performed the world's first serial transverse enteroplasty procedure (STEP), a surgical technique that lengthens the bowels of children with SBS.