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Pyloric stenosis

  • Alternative Names

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


    Vomiting is the first symptom in most children:

    • Vomiting may occur after every feeding or only after some feedings
    • Vomiting usually starts around 3 weeks of age, but may start any time between 1 week and 5 months of age
    • Vomiting is forceful (projectile vomiting)
    • The infant is hungry after vomiting and wants to feed again

    Other symptoms generally appear several weeks after birth and may include:

    • Abdominal pain
    • Belching
    • Constant hunger
    • Dehydration (gets worse with the severity of the vomiting)
    • Failure to gain weight or weight loss
    • Wave-like motion of the abdomen shortly after feeding and just before vomiting occurs

    Signs and tests

    The condition is usually diagnosed before the baby is 6 months old.

    A physical exam may reveal signs of dehydration. The infant may have a swollen belly. The doctor may detect the abnormal pylorus, which feels like an olive-shaped mass, when touching the stomach area.

    An ultrasound of the abdomen may be the first imaging test performed. Other tests that may be done include:

    • Barium x-ray -- reveals a swollen stomach and narrowed pylorus
    • Blood chemistry panel -- often reveals an electrolyte imbalance