When Your Child Has Infantile Hypertrophic Pyloric Stenosis

Cross section of normal stomach.

The pylorus is the valve between the end of the stomach and start of the small intestine. The pylorus opens to let food out of the stomach and into the small intestine. Then it 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. These means the body can’t absorb nutrients, leading to malnutrition. And it can’t absorb fluids, leading to dehydration. Infantile pyloric stenosis can happen when a baby is 1 to 2 months old. Doctors are not sure what causes it, but seems to run in families.

What are the symptoms of infantile hypertrophic pyloric stenosis?

A child with pyloric stenosis may have:

  • Vomiting, often forceful (projectile vomiting)

  • Hunger right after vomiting

  • Loss of weight or poor growth despite good appetite

  • Signs of dehydration such as less urine, very dark urine, dry mouth, and no tears when crying

  • A lot of stomach movements after feeding

How is infantile hypertrophic pyloric stenosis diagnosed?

During a physical exam, the healthcare provider may be able to fee a lump of thickened muscle through the abdominal wall. Your child may need tests such as:

  • 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. This may be done if the lump can't be felt or the ultrasound is not clear.

Cross section of stomach with thickened pylorus.

How is infantile hypertrophic pyloric stenosis treated?

Pyloric stenosis is treated with surgery. The surgery may be done with several small incisions (laparoscopic). Or it may be done with one larger incision (open surgery).

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

After 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, your child can start eating again about 3-4 hours after surgery. Your child 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, your child may still have some vomiting or reflux. Reflux is 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 your child heals. Even after surgery, there is a small chance the muscle around the pylorus will thicken again.

When to call the healthcare provider

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

  • Vomiting that won’t stop or looks green

  • Crying that can’t be soothe, which can mean your child is in severe pain

  • Weight loss or no weight gain

  • No bowel movement within 2-3 days after surgery

  • Signs of dehydration such as less urine, very dark urine, dry mouth, and no tears when crying

  • Low energy

  • Fever of 100.4ºF  (38.0°C) or higher, or as directed by the healthcare provider