Loma Linda University Children's Hospital - Pediatric Surgery - Pyloric Stenosis
Pediatric Surgery

Pyloric stenosis

Pyloric stenosis is a narrowing of the stomach's outlet, which is called the pylorus. This is due to over-development of the surrounding rings of muscle. Vomiting develops when the stomach outlet, squeezed by excessive growth of surrounding muscle, is narrowed enough to interfere with the stomach's ability to empty.

Frequent, projectile vomiting is usually evident between two and eight weeks of age in most infants with this condition. Initial symptoms may be mild in some infants and can be confused with a milk allergy. The cause of pyloric stenosis is unknown. Male infants are affected more often then females, and a history of pyloric stenosis in other family members is common.


Enlargement of the pyloric muscle is the defining feature of pyloric stenosis. If the hypertrophied muscle can be identified by physical examination of the abdomen, imaging studies are usually not necessary. If abdominal examination is not definitive, an ultrasound will be used to identify abnormal thickening and elongation of the pyloric muscle.

Treatment of pyloric stenosis

pyloric stenosisPyloromyotomy is a simple operation designed to cut and release the rings of muscle constricting the pylorus. It is the only effective treatment for pyloric stenosis. No tissue is removed, and the stomach lining is not opened. The pyloric muscle returns to normal size with time.


The operation

Vomiting causes dehydration and loss of important body salts. The lost fluid and salt must be replaced before the pyloromyotomy may be performed. Blood work will be drawn to determine the degree of fluid and electrolyte imbalance. This imbalance will be corrected by intravenous infusion of an appropriate mixture of fluids and electrolytes. Once the fluid and electrolytes have been replaced, then the operation may proceed.

The pyloromyotomy may be done either through a laparoscope or through a small incision in the right side of the upper abdomen. Absorbable stitches are buried beneath the skin, and do not require removal. A watertight clear dressing will be used to cover the incision and your surgeon will instruct you when this outer dressing can be removed.

During the operation, parents are asked to wait in the Children' s Hospital waiting area located on the lobby level. After the operation, your child will be recovered in the Post Anesthesia Care Unit for one to two hours, or if they are newborns, they may be immediately transferred to the Neonatal Intensive Care Unit (3700) for recovery.

The hospital stay

Nurses will make every effort to keep your baby comfortable and pain-free. The pediatric surgery team will make rounds as a group daily. We are available to answer any questions you may have concerning the progress of your baby.


Once your baby is awake (about one hour after the operation), feedings will be started and offered every three hours. As long as your baby tolerates the feedings, they will be increased with each feeding until the "goal" amount is reached. "Spits" are OK, and as long as your baby is tolerating the feedings, they may be discharged home. Vomiting of one or two feedings in the first 24 to 48 hours after the operation is not uncommon, and is not cause for alarm.

Postoperative care


Pain control rarely requires more than over-the-counter pain relievers such as Children's Tylenol or Children's Advil. These may be given every four hours as needed.

Any other medications which your child required before the operation should be continued on the regular schedule afterward.


After discharge, infants usually eat vigorously in an effort to catch up for lost nutrition while they had pyloric stenosis. It is particularly important to burp babies particularly well in the first few days after pyloromyotomy, as they tend to swallow a bit more air and their stomach may be more sensitive to being bloated with air.


No restriction of activity is necessary.

Wound care

Always wash your hands before touching or cleaning the incision area. Some blood staining of the paper tapes on the incision is common. If the blood is dry and not spreading, the staining is not a problem. If the blood seems fresh, the amount is increasing, or if the paper tape is blood soaked and partially floating above the skin, apply gentle pressure with a clean washcloth for five to six minutes. Then, contact the pediatric surgery resident on call (909) 558-4000. The problem is usually minor but the surgeon needs to know about it.


No tub baths should be given for at least two days after the operation. Sponge bathing is permitted the day following the operation. Carefully pat dry the incision tapes after bathing.

When to call your child's surgeon

  • Fever above 101oF that does not come down with Tylenol (mild fever is common)
  • Difficulty breathing, with or without a croupy cough
  • Active bleeding from the incision
  • Redness, swelling, or persistent pain in the incision
  • Persistent vomiting


A clinic appointment needs to be scheduled one to two weeks after the operation. Please call (909) 558-4848 to schedule this appointment if an appointment was not made for you before leaving the hospital.

Common problems in pediatric surgery | Pediatric surgery homepage

| | |