Pyloric stenosis is when the lower part of the stomach (called the pylorus) is too narrow for milk to pass through into the small intestine. Normally, the muscle at the end of the stomach contracts to keep food in the stomach and the muscle relaxes to let food out of the stomach. In pyloric stenosis, the muscle is too big and doesn't relax well. This happens to babies between 2 weeks and 2 months of age. It is also called infantile hypertrophic pyloric stenosis or gastric outlet obstruction.
The cause of this condition is not known. Pyloric stenosis is more likely to occur in firstborn male infants. It also tends to run in families. Hormones from the mother may lead to the condition. It may be that the thickening of the muscle is a type of allergic reaction.
There may be problems with the way the body uses nitric oxide, a chemical that tells the pylorus muscle to relax. This could make the muscle tight almost all the time and cause it to get larger and thicker.
Symptoms of pyloric stenosis generally begin around 3 weeks of age. They include:
The healthcare provider will ask about your child's medical history and recent symptoms. It is very helpful if you can describe the vomiting.
Your baby will probably have a blood test. An ultrasound of the baby's abdomen may be done. A barium study may be done. The baby swallows a small amount of a chalky liquid (barium), and then special X-rays are taken.
The baby will need surgery, called a pyloromyotomy. The surgeon cuts the tight muscle between the stomach and small intestine that is causing the problem. This loosens the muscle so food will be able to pass easily into the small intestine. Babies can usually eat shortly after the surgery.
Call your child's provider if your baby has: