Birth Defects Gastrointestinal Pyloric Stenosis

Congenital defects of the gastrointestinal system can sometimes occur during fetal development. In particular, pyloric stenosis is a defect of the gastrointestinal system that affects the way food moves through the digestive tract.

Pyloric stenosis is a progressive condition that begins to show symptoms soon after birth. Development of pyloric stenosis is influenced by genetics: A baby’s chances of developing it are higher if one of his parents had the condition.

Biology and Symptoms of Pyloric Stenosis

In healthy people, food travels from the mouth, down the esophagus, and to the stomach. There, it mixes with stomach acid in the early stages of digestion, and is passed to the small intestine for further breakdown through a valve called the “pylorus.” In people with pyloric stenosis, muscles of the pylorus thicken gradually over the first several weeks of life, making this opening smaller and smaller until partially digested food from the stomach can no longer pass through to the small intestine.

Though it may not happen after every feeding, forceful vomiting (not typical “spit-up”) is one of the first symptoms of pyloric stenosis. Babies who have this condition can also experience:

  • Changes in bowel movements
  • Constant hunger
  • Dehydration and electrolyte imbalance
  • Difficulty with weight gain
  • Palpable abnormal pylorus (in some cases)
  • Swollen belly
  • Visible waves of peristalsis (rippling motion on the stomach) after feeding as the stomach tries to empty into the small intestine.

If you notice these symptoms in your infant, contact your pediatrician to schedule an examination. Be sure to keep a detailed record of feeding and vomiting episodes, as this information will help the doctor to make a diagnosis.

Pyloric Stenosis Diagnosis and Treatment

When an infant is displaying symptoms of pyloric stenosis, ultrasound can be used to make a definitive diagnosis of a narrowing of the pylorus. A barium x-ray can highlight the path of food through the digestive system, and blood tests can help diagnose an electrolyte imbalance.

A surgical procedure called a “pyloromyotomy” is often performed very soon after diagnosis to expand the pylorus in the affected infant. Pyloric stenosis surgery usually resolves symptoms within a few days. After surgery, vomiting should begin to subside, and the infant should be able to tolerate small, then regular meals.

Pyloromyotomies are now often performed laproscopically, making the pyloric stenosis scar less noticeable. Surgery does involve risks, including bleeding and infection, along with risks associated with general anesthesia. However, the procedure typically has a relatively swift recovery period, and symptoms should not recur after recovery is complete.


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