When Your Child Has Infantile Hypertrophic Pyloric Stenosis

Cross section of normal stomach.

The pylorus is between the end of the stomach and the beginning of the small intestine. The pylorus opens to let food out of the stomach and into the small intestine, then closes. If the muscle around the pylorus thickens, the pylorus can’t open all the way. In children, this problem is called infantile hypertrophic pyloric stenosis. Food can’t leave the stomach to be digested. As a result, the child’s body can’t absorb nutrients (leading to malnutrition) or fluids (leading to dehydration). Infantile pyloric stenosis often happens at around 1 to 2 months of age. Doctors are not sure what causes it, but it does seem to run in families.

What are the symptoms of infantile hypertrophic pyloric stenosis?

A child with pyloric stenosis may have:

  • Vomiting, especially with vomit that shoots out of the child’s mouth (projectile vomit). The child is often hungry right after vomiting.

  • Loss of weight or poor growth due to undernourishment.

  • Signs of dehydration: decreased urination; very dark urine; dry mouth; refusal to drink fluids; no tears when crying.

  • Increased stomach movements or “ripples” after feeding.

How is infantile hypertrophic pyloric stenosis diagnosed?

During an exam, an “olive” (lump) of thickened muscle can sometimes be felt through the abdominal wall. These tests may then be done:

  • Abdominal ultrasound: Sound waves are used to create an image of the inside of the abdomen and the pylorus.

  • Upper GI (gastrointestinal) X-ray: An x-ray image is taken of the top of the small intestine, which shows the pylorus. Usually done if the olive can't be palpated or the ultrasound is not diagnostic, but there is still a strong clinical suspicion.

How is infantile pyloric stenosis treated?

Cross section of stomach with thickened pylorus.

Pyloric stenosis is treated with surgery. The surgery may be done either laparoscopically or as open surgery.

  • If the child is dehydrated, this must be treated before surgery can be done. Fluids are given  through an IV (intravenous) line. These replace the fluids the child’s body has not been able to absorb. Blood tests may also be done to check for problems that dehydration may cause.

  • When the dehydration is treated, surgery is scheduled. During surgery, the thickened muscle is cut. The contents of the stomach can then flow into the intestine. In most cases, the child can start eating again about 3 to 4 hours after surgery. He or she can go home about 24 hours after surgery.

What are the long-term concerns?

After treatment, most children don’t have long-term problems. In the short term, the child may still have some vomiting or reflux (a small amount of liquid coming up from the stomach into the mouth). This is normal for a short time after surgery. It should go away as the child heals. Even after surgery, there is a small chance the muscle around the pylorus will thicken again.

When to call the doctor

After surgery, call the doctor if your child has any of the following:

  • Vomiting that won’t stop or looks green

  • Inconsolable crying (may mean the child is in severe pain)

  • Weight loss or lack of weight gain

  • No bowel movement within 2 to 3 days after surgery

  • Signs of dehydration: decreased urination; very dark urine; dry mouth; refusal to drink fluids; no tears when crying

  • Sluggishness or low energy

  • Fever of 100.4ºF  (38.0°C) or more