Pyloric Stenosis in Babies: Causes, Symptoms, Treatment and Prevention


Stomach is a J-shaped bag which can hold on to and store up to 1.7 liters of content. It has various regions out of which pylorus are the one which connects the stomach and duodenum. Normally it acts as a muscular valve to hold up the food until it is ready to pass on to the intestine. In pyloric stenosis there is unusual thickening of the pylorus part and hence the food is unable to pass to the intestine for further digestion. It can cause problems like forceful vomiting, dehydration and weight loss. Babies with pyloric stenosis seem to be hungry all the time.

All You Need to Know to About Pyloric Stenosis in Babies

pyloric stenosis

Causes of pyloric stenosis in babies

The exact reason behind this abnormal thickening of the stomach muscle is not known but it is believed that abrupt thickening could occur either at birth or early after birth. Also the researchers have even speculated environmental and genetic influence for the condition. There are two types of pyloric stenosis in infants:

  • Congenital pyloric stenosis, or the congenital hypertrophic pyloric stenosis, occurs when the baby has had a thickened pyloric wall right at birth.
  • Acquired pyloric stenosis, also called acquired hypertrophic pyloric stenosis, this is often observed a couple of weeks after birth, when the baby begins to display the initial signs and symptoms of the condition.

Paediatric experts believe that pyloric stenosis is mostly acquired than congenital. Specific factors seem to increase the risk of an infant developing any of the congenital or acquired pyloric stenosis.

Risk factors include


It mostly affects infants of the age group of a few weeks to six months old. Peak incidence being among babies three to five weeks old.



If any of the parents had pyloric stenosis, then the baby has a 20% higher chance of developing it. Hereditary pyloric happens due to faulty and abnormal genes and are transmitted through generations down the line.

  • Among gender, baby boys are at four time larger risk than the girl child.
  • Preterm baby are highly susceptible
  • First born babies
  • Smoking during pregnancy
  • Exposure to certain drugs like erythromycin during initial weeks of life of the newly born infant.
  • A mother consuming erythromycin during the last weeks of pregnancy or during the first month of lactation also increases the risk to precipitate the stenosis in babies.

Symptoms of pyloric stenosis in babies

Signs and symptoms of pyloric stenosis usually appear within three to five weeks after the baby is born. Pyloric stenosis is rare in infants older than age 3 months.

Signs and symptoms include:

Vomiting immediately after feeding

The baby may vomit forcefully, ejecting breast milk up to several feet away which is known as projectile type vomiting. The problem might be mild at first but may gradually become more severe as the pylorus starts narrowing. The vomits can at times contain blood.

Persistently hungry

 Babies who have pyloric stenosis often want to be fed soon after they have vomited.

Stomach contractions

Noticeable wave-like contractions (peristalsis) that crease across your baby’s abdomen soon after feeding but before vomiting. This is due to the stomach muscles trying to force the food out through the narrow pylorus.



Your baby might cry without tears or become tired, all this because he is severely dehydrated from all the throwing up. There’s even lesser frequency and quantity of urine he/she is passing.

Changes in bowel movements

Since in pyloric stenosis food is prevented from reaching the intestines, babies are usually constipated.

Weight problems

Pyloric stenosis can keep a baby not only from gaining weight but sometimes can even lead to weight loss.

Diagnosis of pyloric stenosis in babies

Doctor will start with a routine physical examination. The doctor can feel an olive-shaped lump and the peristaltic waves in the baby’s abdomen which are most obvious sign of pyloric stenosis.

The doctor might also recommend:

  • Blood tests to check dehydration and electrolyte imbalance or both
  • Ultrasound to view the pylorus and confirm the diagnosis
  • X-rays of the baby’s abdomen, if ultrasound report aren’t clear

Treatment of pyloric stenosis in babies


Surgery is needed to treat pyloric stenosis. This surgery is often scheduled on the same day as the diagnostic test. If the baby is dehydrated or has an electrolyte imbalance, he/she will even have a fluid replacement before this surgical process.


Here, the surgeon cuts through the outside of the thickened pylorus muscle, allowing the inner side to bulge out. This opens up a channel for the food to pass through the small intestine.

Pyloromyotomy is often minimally invasive surgery. A slender viewing instrument called laparoscope is inserted through an incision near the baby’s belly bottom. This process has additional advantages like:

  • Recovery from this procedure is usually quicker than from traditional surgery
  • It leaves a smaller scar.

After surgery

  • Your baby might be given IV fluids for a few hours or until he or she can eat. You can probably start feeding your baby again within 12 to 24 hours.
  • Your baby might want to feed more often.

Common complications due to pyloric stenosis surgery are bleeding and infection. However, complications are quiet unusual, and the results of surgery are known to be excellent.

Prevention of pyloric stenosis in babies

As the condition occurs unpredictably and the reasons behind it are unknown, it cannot be prevented. However, you can minimize the risk. Do remember that:

  • Pregnant mothers are not smoking.
  • Taking erythromycin during pregnancy should be avoided.
  • Have scheduled baby checkups with the paediatrician. Timely detection ensures less suffering and a speedy recovery.
Hope this article was of help for all our parents!! Please share your comments/queries/tips with us and help us create a world full of Happy and Healthy Babies!!