What Is Pyloric Stenosis?

Pyloric stenosis is the narrowing of part of the stomach (the pylorus) that leads into the small intestines. This narrowing occurs because the muscle around the pylorus has grown too large. Most babies with pyloric stenosis begin to vomit during the second to third week of life. Babies begin with "spitting up" that turns into forceful projectile vomiting. The vomiting occurs after feeding. Sometimes, in formula-fed infants, different kinds of formula are tried without any change noted.

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How Is Pyloric Stenosis Diagnosed?

The diagnosis of pyloric stenosis is made when an infant has a history of progressive forceful vomiting. The pyloric valve (opening at the bottom of the stomach that regulates the stomach emptying) becomes bigger over time and blocks the stomach from emptying. The baby begins to lose weight, and may become dehydrated. Dehydrated means the baby is not keeping enough fluid in his body. The baby may show signs of being sleepy or not be as active as usual. The baby may not have had a wet diaper in several hours and the soft spot on the top of his head may be sunken.

A physical exam by the doctor sometimes shows an enlarged pyloric valve. You may hear the doctor say that it feels like an olive because that’s the way it feels in shape and firmness. Sometimes it is hard to examine the baby if he has a stomach full of breast milk/formula or air and it is necessary to place a small nasogastric (NG) tube. The NG tube is a small plastic tube that goes through the infant’s nose or mouth into their stomach. It helps the stomach empty by draining air or anything else that may be in it.

The doctor may do tests to determine if the baby has pyloric stenosis. One test is a barium study or upper GI. This test involves the baby drinking a small amount of barium (a white, chalky liquid) that shows up easily on an X-ray picture. This test can tell the doctor if the baby has pyloric stenosis or another condition called gastroesophageal reflux (GER). GER is when the contents of the stomach come back up the esophagus.

Another test that may be done is an abdominal ultrasound. This test involves a metal wand that is moved over the baby’s stomach. The metal wand is able to take pictures using sound waves. It is a common test used in pregnancy to look at the baby and does not harm the baby.

How Is Pyloric Stenosis Treated?

If a diagnosis of pyloric stenosis is made, the baby will have some blood work done to check for dehydration. A catheter will be placed into the vein (IV) to replace fluids that the baby needs. The baby may go to surgery that day or the following day. It is very important that the baby not drink anything until after surgery.

The operation is called a pyloromyotomy (pie-lore-oh-my-ot-toe-me). This operation spreads open the muscle around the pyloric valve of the stomach. The incision is about 1 inch long either right around the belly button or on the right hand side of the abdomen. Stitches that dissolve are used, so they won’t have to be removed later.

Feedings will start slowly . Your nurse will tell you when to start. The amount of breast milk or formula will be limited at first and will be increased with each feed. A few episodes of vomiting shortly after surgery are not uncommon but resolve quickly. Most babies can be discharged home 1-2 days after surgery and have no long term problems.

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If you have any questions, use the online tool below to help us connect with you. To refer a patient or schedule an appointment, please contact our clinic using the information below.

  • UT Physicians Pediatric Specialists 
    Texas Medical Center

    6410 Fannin St., Suite 500
    Houston, Texas 77030
    Phone: (832) 325-6516
  • UT Physicians Pediatric Surgery
    Texas Medical Center

    6410 Fannin St., Suite 950
    Houston, Texas 77030
    Phone: (832) 325-7234

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