MedlinePlus Medical Encyclopedia: Pyloric stenosis

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Pyloric stenosis

Contents of this page:
Illustrations Alternative names Definition Causes, incidence, and risk factors Symptoms	Signs and tests Treatment Expectations (prognosis) Complications Calling your health care provider

Illustrations

Digestive system

Pyloric stenosis

Pyloric stenosis - series

Alternative names Return to top

Congenital hypertrophic pyloric stenosis; Hypertrophic pyloric stenosis; Gastric outlet obstruction

Definition Return to top

Pyloric stenosis is a narrowing of the outlet from the stomach to the small intestine (called the pylorus). The condition primarily occurs in infants.

Causes, incidence, and risk factors Return to top

This condition is caused by a thickening of the muscles of the pylorus. This prevents the stomach from emptying into the small intestine.

The cause of the thickening is unknown, although genetic factors may play a role. It occurs more commonly in boys than in girls and is rare in patients older than 6 months.

Approximately 2 to 3 of every 1,000 infants has pyloric stenosis.

Symptoms Return to top

Symptoms generally appear several weeks after birth:

Vomiting
- Usually mild at first, becoming progressively more forceful within one half hour of feeding
- Projectile vomiting
Infant appears constantly hungry
Diarrhea (loose green stools)
Wave-like motion of the abdomen shortly after feeding and just before vomiting occurs
Dehydration (becoming more profound with the severity of the vomiting)
Failure to gain weight or weight loss

Additional symptoms that may be associated with this condition:

Abdominal fullness prematurely after meals
Belching
Apparent abdominal pain

Signs and tests Return to top

Physical examination may show signs of dehydration. The infant may have a distended abdomen. Palpation of the abdomen may reveal the abnormal pylorus, which feels like an olive-shaped mass.

A chemistry panel often reveals electrolyte imbalances.
An ultrasound of abdomen may be the first imaging test performed.
A barium X-ray reveals a distended stomach and narrowed pylorus.

Treatment Return to top

Treatment for pyloric stenosis involves surgery to split the overdeveloped muscles of the pylorus is the treatment for this disorder. Rehydration with intravenous fluids usually takes place prior to surgery.

Small, frequent feedings are usually well tolerated several hours after the surgery.

Expectations (prognosis) Return to top

Surgical repair usually provides complete relief of symptoms.

Complications Return to top

Postoperative vomiting (This is very common and generally improves with time.)
Failure to gain weight in the newborn period
Risks associated with any surgery

Calling your health care provider Return to top

Call your health care provider if symptoms suggestive of pyloric stenosis develop in your infant.

Update Date: 6/18/2004

Updated by: A.D.A.M. Editorial and Jonathan Fanaroff, M.D., Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, OH. Review provided by VeriMed Healthcare Network (12/30/2002).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2002 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.