Better Me

Does My Baby Have Acid Reflux or Pyloric Stenosis?

Spitting up is common in healthy babies. It’s why we have bibs and burp cloths, right? But what if your baby isn’t just spitting up—they’re projectile vomiting? This can’t be normal, right?

During your baby’s first eight weeks of life, they may experience reflux or gastroesophageal reflux disease, or GERD, a condition where contents in the stomach come back up and can cause spit up. However, if the spit up is frequent and forceful and you notice your baby is always hungry, they could have a rare condition called pyloric stenosis.

While spit up from time to time isn’t necessarily a cause for concern, those with pyloric stenosis need immediate medical treatment. Here’s what you should know.

What is pyloric stenosis?

Pyloric stenosis is a condition that affects the gastrointestinal tract that typically occurs from two weeks to eight weeks of age but can be seen occasionally in babies a little older or younger, said Stuart Lacey, MD, a pediatric general surgeon with Banner Children's. It’s caused by a narrowing of the pylorus—a muscle in the wall of the stomach where it empties into the small intestines.

“The purpose of the pylorus is to squeeze and close to keep food in the stomach until the stomach has done its part of digestion. Then the muscle relaxes and lets food through into the intestines,” Dr. Lacey said. “In pyloric stenosis, the muscle hypertrophies (or overgrows) and becomes so thick it can’t relax so the stomach can’t empty. This leads to excessive, projectile vomiting in infants.”

What are the signs of pyloric stenosis?

The first symptom of pyloric stenosis is usually projectile vomiting shortly after your baby eats. Unlike other reasons for vomiting, you may notice your baby is usually hungry again soon after throwing up and will want to eat. Because pyloric stenosis prevents fluids and nutrients from reaching the intestines, other symptoms may include dehydration, constipation and weight loss.

“No matter the cause, when babies are vomiting more than they are keeping down, when they aren’t voiding much urine or when they are failing to gain weight from excessive vomiting, a parent should have their baby observed by their treating physician,” Dr. Lacey said.

How does GERD differ from pyloric stenosis?

They can be hard to tell apart, but forceful vomiting is usually more typical of pyloric stenosis.

What causes pyloric stenosis?

The causes of pyloric stenosis aren’t well known, but it does sometimes run in families. According to the National Institutes of Health, it occurs in 2 to 5 per 1,000 live births each year and is more common in males than females.

How is pyloric stenosis diagnosed?

Your baby’s doctor will perform a physical examination and will ask detailed questions about your baby’s feeding and vomiting patterns. They’ll look for any weight loss or failure to maintain growth and will check for a lump in the abdomen. Typically, if there is a lump, it will feel like an olive, firm and movable. When pyloric stenosis seems likely, an abdominal ultrasound is usually done to confirm.

How is pyloric stenosis treated?

The most effective treatment is a minimally invasive surgical procedure called a pyloromyotomy, where a pediatric surgeon cuts the pyloric muscle to allow the pylorus to reopen.

“It is a relatively small operation and recovery is very rapid,” Dr. Lacey said. “Most babies go home the next day. And once the operation is done, the baby is cured for life.”


If you’re little one is forcefully vomiting, don’t delay speaking with your baby’s doctor. It is important to diagnose pyloric stenosis early, before your baby becomes dehydrated or loses too much weight. With prompt treatment, your baby can continue to eat, grow and thrive.

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