Pyloric Stenosis

Pyloric stenosis is the narrowing of the lower portion of the stomach (pylorus) that leads into the small intestine. The muscles in this part of the stomach thicken, narrowing the opening of the pylorus and preventing food from moving from the stomach to the intestine.

This problem typically occurs in infants between 2 and 8 weeks of age and affects 1 out of every 500 to 1,000 live births.

No particular cause of pyloric stenosis has been clearly identified, though both genetic and environmental factors are thought to be involved. It is known, however, that there is nothing that can be done to prevent its occurrence. Pyloric stenosis is considered a multifactorial trait, which means that many factors are involved. Pyloric stenosis is four times more common in males than in females. Caucasians seem to develop pyloric stenosis more frequently than babies of other races.

Due to the hereditary factor, several members of a family may have had this problem in infancy.

If a child with pyloric stenosis is female:

  • The likelihood of having a future son with pyloric stenosis is 1 in 5
  • The likelihood of having a future daughter with pyloric stenosis is 1 in 14

If a child with pyloric stenosis is male:

  • The likelihood of having a future son with pyloric stenosis is 1 in 20
  • The likelihood of having a future daughter with pyloric stenosis is 1 in 40

Since the stomach opening becomes blocked, food cannot move into the intestine. This causes a baby with pyloric stenosis to vomit forcefully after eating. This vomit is quite different from a “wet burp” that a baby may have at the end of a feeding. The baby is usually quite hungry and eats or nurses eagerly. Large amounts of breast milk or formula are then vomited and may go several feet across a room. The milk is sometimes curdled in appearance due to the fact that it remains in the stomach where it is exposed to acid.

As a result of this vomiting, several problems can arise. The most serious problem is dehydration (excessive water loss from the body). A baby who vomits regularly will not get sufficient fluids to meet his/her nutritional needs. Additionally, minerals that the body needs to stay healthy, such as potassium and sodium, are lost through vomiting. Lacking an adequate amount of both water and minerals can cause infants to lose weight and to become extremely sick very quickly.

Other symptoms include:

  • Weight loss
  • Lethargy (lack of energy)
  • Fewer bowel movements
  • Constipation
  • Mild jaundice (yellowish coloring in skin)

Pyloric stenosis is treated in two stages. First, fluids are given intravenously to treat dehydration and restore the body’s normal chemistry. Once this is done, an operation called a pyloromyotomy is performed. This opens up the tight muscle that has caused the narrowing in the stomach, allowing the passage of food from the stomach to the intestine. This surgery can be performed using either an open or laparoscopic surgical approach.

Within two hours after surgery, small amounts of milk or liquids are given. Over a 24- to 48-hour period, feedings are gradually increased. As soon as your baby can tolerate normal feedings (usually one to two days after surgery), he/she will be discharged from the hospital. After discharge, it is strongly recommended to do no more than 3 ounces every 3 hours for the next 3 days.

Although a baby often vomits for 24 to 48 hours after surgery, this usually disappears without any further treatment. Occasionally, however, vomiting may persist for 4 to 5 days.

Your baby’s incision should be kept clean and dry, and no tub baths should be given for one week after surgery. Steri-strips (bandage-like tape) that are placed over the incision should be left in place and then removed according to the instructions of your pediatric surgeon. They are generally left in place for 7 to 10 days.

There are no long-term effects of surgery, and there is less than a 1% chance that pyloric stenosis will recur.

Call your child’s doctor if:

  • Your baby’s temperature is above 101° F (38.6° C), even if it drops below this when acetaminophen is given
  • There is an increase in redness, swelling or drainage at the incision site or if this site has drainage with a foul odor
  • Pain is not relieved by medication
  • There are signs of dehydration such as fewer wet diapers each day, the absence of tears when crying, or a fontanel (soft spot on the head) that appears sunken
  • Vomiting occurs with more than three consecutive feedings or lasts longer than 48 hours after discharge