Pediatric GI Flashcards
Normal pediatric bowel movement patterns:
● Newborns: Around 4 stools daily
● 0-3 months old:
○ Breastfed - average of 3 stools per day.
○ Formula-fed - average of 2 stools per day
● By age 2: usually average less than 2 BMs per day
● After age 4: average is slightly more than once a day
Constipation is characterized by at least one of the following:
○ Difficult/painful defecation
○ Infrequent stools (often two or fewer per week)
○ Seemingly incomplete defecation
○ Passing large-caliber and hard stools (often with excessive straining)
Functional Constipation
● No evidence of a primary anatomic or biochemical cause.
● Common Timing of Presentation:
○ Introduction of solid food in infants
○ During toilet training
○ Beginning school
○ Significant Life Stressors
Contributing Factors to functional constipation
○ Painful Defecation from fissures, irritation, abuse, or hemorrhoids
■ Leads to withholding stool (Behavioral)
○ Toilet Training Issues
○ Dietary Factors: Large amounts of highly processed foods, less fruits,
vegetables, and fiber, and/or reduced fluid intake
Infant dyschezia
Ineffective defecation, with straining in the absence of hard stools/constipation.
● A functional disorder, characterized by at least 10 minutes of straining and
crying before successful or unsuccessful passage of soft stools
● Occurs in infants younger than nine months old.
● Likely caused by failure to relax the pelvic floor during the defecation.
● Infants naturally have weaker abdominal muscle tone
Non-Functional (Organic) Constipation
● Secondary to an underlying pathology.
● Accounts for less than 5% of pediatric constipation.
● More likely to present in the first months of life.
Most Common Organic Causes of Non-Functional (Organic) Constipation
● Hirschsprung Disease
● Food Intolerances (including to cow’s
milk) and Celiac Disease
● Anorectal anomalies, including
imperforate or displaced anus
● Metabolic or endocrine abnormalities
(lead poisoning, hypokalemia,
↑or↓calcium, hypothyroidism
Constipation history clues:
● May have overflow fecal incontinence (Can appear like they have diarrhea)
● Bladder issues such as nocturnal enuresis or symptoms of UTI can actually be
due to or co-occur with functional constipation (bowel bladder dysfunction).
Treating the constipation can often resolve bladder dysfunction.
● Apparent straining for an infant during defecation does not necessarily indicate
constipation (if soft stool, think dyschezia)
Constipation abdominal exam:
● Abdominal exam: auscultate, palpate for pain (often LLQ), distention, or masses
○ Dullness to percussion can indicate impaction, obstruction, or constipation
In peds with constipation, hair tuft or a “pit” superior to the sacrum can _____
indicate occult spinal dysraphism (Spina Bifida)
“Red Flag” constipation exam findings that should lead to further work-up:
● Rectal bleeding (unless attributable to an anal fissure)
● Severe abdominal distension
● Stools with very narrow diameter - “Ribbon Stools”
● Weight loss, poor weight gain, or delayed growth
● Abnormal anal position
What is the likely cause of Delayed passage of meconium, tight sphincter, empty or narrow ampulla?
Hirschsprung disease
Diagnostic Studies for Constipation
● Testing is reserved for patients with suspected Non-Functional Constipation
● Depending on symptoms, may include:
○ Thyroid Panel (TSH, fT4)
○ Serum Calcium level
○ Celiac Disease Testing
○ Dairy Allergy Testing
○ Sweat Chloride Testing
○ Abdominal X-ray (if over 1 year old)
○ Barium Enema
Treatment of Non-Functional Constipation is _____
based on the underlying disease and
may require urgent intervention.
Treatment of Functional Constipation in Infants:
● Often respond to sorbitol-containing foods or juices (eg. apple, prune, or pear)
● Osmotic laxatives like Lactulose or sorbitol. Polyethylene glycol 3350 (Miralax)
can be used after 6 months old.
● Glycerin suppositories can be effective, but should not be used frequently
Constipation - Management
PED-GI-1
Warning: infants can become conditioned to depend on this!
Treating Functional Constipation in Children:
● Parental education and behavioral interventions
○ Behavior management in children over 1 year if it’s contributing.
■ Scheduled toileting routines and positive reinforcement
■ Educate parents and remove negative attributions
● Dietary modifications are recommended for all patients
● Polyethylene glycol (PEG, Miralax)
Osmotic laxative use in children:
● Chronic or prolonged treatment with osmotic laxatives is considered safe and
effective, including Miralax, magnesium hydroxide, and lactulose
Imperforate Anus
Anorectal malformations include a wide spectrum of birth defects that can
occur with the anus.
● Sometimes the malformation is an
incomplete opening, or no opening
at all.
Imperforate Anus pathophysiology
Likely due to early termination of the caudal descent of
the urorectal septum due embryologic development
Characteristic Signs and Symptoms of Imperforate Anus
● Meconium not being passed within the first
24-48 hours after birth.
● Missing or malpositioned anal opening.
● Stool passing from the vagina, penis, or
scrotum.
● Abdominal distention
● Associated anomalies: VACTERL
Imperforate Anus Diagnosis
● History and physical exam is usually sufficient for picking up the
diagnosis of imperforate anus. However…
● It is important to order certain diagnostic tests to evaluate the extent of the malformation and to look for
other developmental deformities:
○ Abdominal ultrasound (fistulas)
○ Abdominal X-ray
○ Spinal Ultrasound or MRI
○ Consider cystourethrography
Management of Imperforate Anus
● Once imperforate anus has been identified, the newborn should NOT be fed,
but should receive IV fluids for hydration. (NPO)
● Treat life-threatening co-morbidities first
● Pediatric gastrointestinal surgeon should be urgently consulted.
● Definitive treatment requires surgery
● Prognosis is generally good and long-term, normal bowel functioning is common.
Hirschsprung Disease
● Sometimes called Congenital Aganglionic Megacolon, it is a motor disorder
of the colon.
● It is caused by congenital absence of the lower intestine innervation
● Characterized by absence of neurologic ganglia
that normally innervate the colonic bowel wall.
Hirschsprung Disease Pathophysiology
● Normally, several neural networks innervate the intestine, including the Meissner plexus and Auerbach plexus.
● These stimulate intestinal motility under the direction of the autonomic nervous system.
● In Hirschsprung Disease, these neural networks are congenitally absent, resulting in loss of intestinal motor function, and collapsed/narrow rectum
● Most often occurs in the rectosigmoid colon, but can occur in other areas as well
Characteristic Signs and Symptoms of Hirschsprung Disease
● Most common presentation is delayed passage of the meconium at birth
(>48 hours), or in an infant struggling with constipation since birth
● Other symptoms can include:
○ Bowel obstruction with bilious vomiting
○ Abdominal distention
○ Poor feeding or failure to thrive
○ Explosive expulsion of gas/stool after DRE (the “squirt” or “blast” sign)
Characteristic Signs and Symptoms -
● The severity depends on the amount of intestines affected
Hirschsprung Disease Diagnosis
● Rectal biopsy is the gold standard for diagnosis.
○ This will reveal the absence of ganglion cells.
● Abdominal X-rays with contrast enema
will likely show distended loops of bowel
with decreased gas present in the rectum
