PANRE/PANCE – Gastroenterology part 4 – Pyloric Stenosis, Intussusception, Phenylketonuria and Hirschprung’s disease

by Isabella on June 14, 2012

Hi fellow study budies, welcome to part 4 of the GI series.  Anyone want GI to be over already?  I do….I do.  But we have many more topics to cover, so we gotta bear through it.  Before we start…here’s a recap of Gastroenterology part 3 :

P.A. Students "Running" Towards Their Goal

So yesterday, my little boy was having some digestive issues, some reflux, some constipation and some general cranky crying.  Thankfully, some singing, hugging and kisses calmed him down and after having one of our pre-sleep goo goo gaa gaa conversations he fell right asleep. In light of last night’s events, I decided to focus this GI lecture on topics that deal with babies or kids.  These are issues that you may deal with either as a parent, or as a PA in peds, GI, ER or family medicine.  Lets start…

Pyloric Stenosis:

  • Pyloric Stenosis is a narrowing and thickening of the pylorus – connection between stomach and small intestine
    • this narrowing and thickening delays gastric emptying and slows its progression into small intestine
    • Usually occurs in newborns anywhere from 4-6 weeks old, but occasionally occurs earlier/later
    • males affected more frequently than femlae
    • Can cause dehydration and failure to thrive if not promptly taken care of
  • Symptoms/Signs:
    • vomiting, often projectile that occurs shortly after a meal
    • after vomiting, infant is still hungry as food hasn’t entered small intestine for absorption
    • on exam, you may be able to palpate an “olive shaped” mass LUQ around umbilicus
    • weight loss noted on exam from previous exam
  • Diagnosis:
    • an abodminal US will usually show the thickening
    • Barium swallow will show a typical “string sign” – narrow portion through which food is slowly passing into intestine
    • CMP – will be consistent with electrolyte imbalance due to dehydration
  • Treatment: surgical repair


  • Intussusception occurs when one part of the intestine telescopes into itself – creating blockage
    • more common in boys
  • Symptoms/Signs:
    • abdominal pain – babies will usually start crying all of a sudden and cannot be comforted, grunting
    • vomiting
    • bloody “Currant Jelly” stool – intussusception causes ischemia of intestine and mucosa sloughs off and mixes with stool
    • on exam you may feel a “sausage like mass”
  • Diagnosis:
    • Abdominal xray may show obstruction
    • US may show the intussusception
    • Barium enema can be both diagnostic and therapeutic in children – not a test of choice in adults due to likely neoplasm causing intussusception
  • Treatment:
    • Hospitalization and IV hydration
    • If Barium enema not successful – surgery
    • Adults – surgery


  • Phenylketonuria is a condition where a baby is born without the ability to break down the amino acid phenylalanine
    • Inherited autosomal recessive trait
    • missing enzyme Phenylalanine Hydrolase
    • metabolites of amino acid accumulate in nervous system – can cause brain damage and movement disorders
  • Symptoms/Signs:
    • Baby with PKU doesn’t usually display symptoms until 2-3 months
    • Amino acid has a part in production of melanin and since it can’t be broken down -
      • Babies often have blonde hair and blue eyes (or lighter than the rest of their family members)
    • Mental retardation, jerking movements of limbs, microcephaly
    • “mousy” odor to breath, skin, and urine – smells musty – like old gym clothes
    • may be prone to eczema
  • Diagnosis:
    • All babies get a PKU test before leaving the hospital – is positive further blood tests are going to be done
  • Treatment:
    • The rule is “diet for life”
      •  babies have to adhere to a diet low in phenylalanine
      • special formula is available
      • foods such as: milk, eggs, artificial sweetners (asparmate)

Hirschprung’s Disease:

  • Hirschprung’s disease is a congenital condition (present at birth) in which the nerve innervations that are responsible for the colon contracting are absent (Meissner’s and Auerbach’s autonomic plexuses)
    • leads to improper peristalsis
    • leads to bowel obstruction (causes 25% of bowel obstructions in newborn)
  • Symptoms/Signs:
    • no meconium after birth
    • no BM within 24-48 hours of birth
    • vomiting
    • poor weight gain and failure to thrive
  • Diagnosis:
    • anal monometry or rectal exam shows low muscle tone in the rectum
    • rectal biopsy – shows absence of autonomic plexuses
  • Treatment: resection of affected bowel
  • Isabella

    So I am writing a PS to clarify the mousy odor for PKU – it basically smells like a musty closet, filled with old sweaty gym clothes. So mousy is a nicer way of putting it :)

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