Chapter 40
Alterations of Digestive Function in
Children
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Overview
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Congenital anomalies
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Structural and functional alterations
• Cleft lip and palate
• Esophageal atresia
• Tracheoesophageal fistula
• Pyloric stenosis
• Aganglionic megacolon
• Imperforate anus
 Enzyme deficiencies
 Infections
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Cleft Lip and Cleft Palate
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Cleft lip and cleft palate are developmental
anomalies of the first brachial arch
Both caused by multiple gene-environment
interactions
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Maternal alcohol and tobacco use, maternal
diabetes mellitus, and variations in the
transforming growth factor-alpha (TGF-α) gene
These factors reduce the amount of neural crest
mesenchyme that migrates into the area that will
develop into the face of the embryo
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Cleft Lip and Cleft Palate
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Cleft lip
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Caused by the incomplete fusion of the
nasomedial or intermaxillary process during the
second month of development
Commonly occurs under one lip, but the defect
can be bilateral and symmetric or asymmetric
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Cleft Lip and Cleft Palate
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Cleft palate
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Commonly associated with cleft lip, but can occur
without it
Results from incomplete fusion of primary palatal
shelves during the third month of gestation
Infant feeding difficulties and infections are
associated with cleft palate
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Esophageal Malformations
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Esophageal atresia
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The esophagus ends in a blind pouch
Tracheoesophageal fistula
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Abnormal connection between the trachea and the
esophagus
Various forms
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Esophageal Atresia and
Tracheoesophageal Fistula
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Pyloric Stenosis
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Cause unknown
Males: 5/5000; females 1/5000
Risk factors
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Increased gastrin secretion by mother in last trimester
 Overproduction of gastric secretions in infant may be
caused by stress-related factors in the mother
 Exogenous administration of prostaglandin E
 Down syndrome
 6.9% of children have a parent who had pyloric
stenosis, 4.9% have a close relative that is affected
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Pyloric Stenosis
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Obstruction of the pylorus because of
hypertrophy of the pyloric sphincter muscle
Circular muscle of pylorus grossly enlarged
because of increased cell size (hypertrophy) and
cell number (hyperplasia)
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TGF-α helps stimulate this increase in muscle mass
Mucosal lining of pyloric opening is folded and
lumen is narrowed by the encroaching muscle
Due to extra peristaltic effort needed to force
gastric contents through the narrow pylorus, the
stomach muscle layers may be hypertrophied
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Pyloric Stenosis
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Child begins projectile vomiting (3-4 feet) at 2 to
3 weeks of age
Vomiting causes weight loss, electrolyte
imbalances, and dehydration
On examination, the hypertrophic pylorus is
palpable in the right upper quadrant
Surgery and fluid administration often necessary
for treatment
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Pyloric Stenosis
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In severe untreated cases, increased gastric
peristalsis and vomiting lead to severe fluid and
electrolyte imbalances (hypochloremic metabolic
alkalosis), chronic malnutrition, and weight loss
Can be fatal within 4 to 6 weeks
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Malrotation
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During embryonic development, ileum and cecum
normally rotate so cecum is in the right lower
quadrant, fixed to abdomen by the mesentery
Malrotation
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Normal rotation does not occur
• Periduodenal band
The malrotated intestine can easily twist due to a poor
connection
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Meconium Ileus
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Meconium: substance that fills the intestine
before birth; a collection of intestinal gland
secretions and amniotic fluid
Meconium ileus is a meconium-caused
intestinal obstruction in a newborn
Caused by lack of digestive enzymes during
fetal life
Common in cystic fibrosis newborns (10%15%)
Usually treated with hyperosmolar enemas
using fluoroscopy
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Distal Intestinal Obstruction
Syndrome
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Formerly called meconium ileus equivalent
With the syndrome, intestinal contents become
abnormally thick and impact the intestinal lumen
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Impactions frequently occur after periods of
dehydration and lack of pancreatic enzymes
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Congenital Aganglionic
Megacolon
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Also called Hirschsprung disease
1 in 5000 live births
Increased incidence in males, siblings of
children with Hirschsprung disease, and
children with Down syndrome
Cause is unknown but multiple interacting
factors and a complex inheritance pattern
involving the RET proto-oncogene have been
found
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Congenital Aganglionic
Megacolon
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Caused by failure of the parasympathetic
nervous system to form intramural ganglion cells
in the enteric nerve plexuses
The aganglionic section of colon is immotile and
an obstruction will likely occur
The intestinal segment proximal to the segment
lacking ganglion cells is dilated and
hypertrophied
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Congenital Aganglionic Megacolon
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Anorectal Malformations
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Anal or rectal agenesis, atresia, and fistula
40% of infants born with anorectal
malformations have other anomalies
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Down syndrome, congenital heart disease, renal
abnormalities, cryptorchidism, esophageal atresia,
spine malformations
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Anorectal Malformations
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Intussusception
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Telescoping or invagination of one part of the
intestine to another; causes obstruction
The most common scenario is the ileum
invaginating into the cecum
80% to 90% of intestinal obstructions in
infants and children are intussusception
Similar to megacolon, the blockage can
cause an obstruction of blood and lymphatic
flow
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Gastroesophageal Reflux Disease
(GERD)
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Related to dilation of the esophagus and reflux
of stomach contents
In newborns, reflux is normal because
neuromuscular control of the gastroesophageal
sphincter is not fully developed
Newborns with GERD vomit excessively
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Cystic Fibrosis
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A genetically transmitted disease (mutation of
the long arm of chromosome 7); involves
many organs and systems
Usually causes death in childhood or young
adulthood
Most common cause of chronic suppurative
lung disease in children and is the most
common life-threatening inherited disease in
the white population
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Cystic Fibrosis
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In the digestive tract it causes a deficiency of
pancreatic enzymes
Triad
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Pancreatic enzyme deficiency
Overproduction of mucus in the respiratory tract
Abnormally elevated sodium and chloride
concentrations
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Cystic Fibrosis
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Pancreatic function may range from normal to
completely ablated
85% of people have pancreatic insufficiency
Obstruction of the pancreatic ducts with thick
mucus blocks the flow of pancreatic enzymes
and causes degenerative and fibrotic changes
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Pancreatic damage eventually can affect the beta
cells, resulting in diabetes mellitus
Diabetes mellitus and cirrhosis have increased as
larger numbers of people with cystic fibrosis have
moved into young and middle adulthood
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Gluten-Sensitive Enteropathy
(Celiac Disease)
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Discovered during WWII food rationing (ill
children improved); began the movement for
nutritional labeling
1% of the population or 1 in 100 children
Involves cellular and humoral immunity
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Gluten-Sensitive Enteropathy
(Celiac Disease)
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Gluten is the protein component in cereal grains
(wheat, rye, barley, oats, malt)
Person loses villous epithelium in the intestinal
tract; gluten protein acts as a toxin
Appears to be caused by dietary, genetic, and
immunologic factors
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Gluten-Sensitive Enteropathy
(Celiac Disease)
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Children fail to grow and thrive; also exhibit
malabsorption symptoms (rickets, bleeding, or
anemia)
Confirmation by performing a tissue biopsy
Person is put on a restrictive diet, and vitamin D,
iron, and folic acid supplements are given
Celiac crisis results in severe diarrhea,
dehydration, malabsorption, and protein loss
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Gluten-Sensitive Enteropathy
(Celiac Disease)
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Kwashiorkor and Marasmus
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Types of malnutrition associated with longterm starvation
Known collectively as protein energy
malnutrition (PEM)
Kwashiorkor is a severe protein deficiency
Marasmus is a deficiency of all nutrients
Stunted physical and mental development
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Kwashiorkor and Marasmus
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Kwashiorkor: lack of proteins causes liver to
swell due to the inability to produce
lipoproteins for cholesterol synthesis
Marasmus: liver function continues, but
overall caloric intake is too low to support
cellular protein synthesis
Presence of subcutaneous fat, hepatomegaly,
and fatty liver differentiates the two
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Failure to Thrive (FTT)
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Inadequate physical development of an infant
or child
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Deceleration in weight gain, low weight/height
ratio, or low weight/height/head circumference
ratio
Organic FTT
Inorganic FTT
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Necrotizing Enterocolitis
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Most common GI emergency of the newborn
Thought to be from reduced mucosal blood
flow
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Ischemia leads to inflammation and necrosis of
the intestinal segments
Contributing factors
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Infections, immature immunity, maternal age >35
years, perinatal stress, and the effects of
medications and feeding practices
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Diarrhea
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Prolonged diarrhea very dangerous
Children have lower fluid reserves than adults
Infant diarrhea
Infectious diarrhea
Acute diarrhea
Rotavirus
Chronic diarrhea
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Primary Lactose Intolerance
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The inability to digest milk sugar
Caused by the inadequate production of
lactase, the enzyme that catabolizes lactose
Malabsorbed lactose causes osmotic
diarrhea, abdominal pain, bloating, and
flatulence
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Physiologic Jaundice of the
Newborn
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A benign, transient icterus that occurs during the
first week of life in otherwise healthy, full-term
infants
Mild unconjugated hyperbilirubinemia
Kernicterus
Usually treated by phototherapy
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Biliary Atresia
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Congenital malformation characterized by the
absence or obstruction of the intrahepatic or
extrahepatic bile ducts
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Plugging, inflammation, and fibrosis of the bile
canaliculi, and extrahepatic biliary tree
Jaundice is the primary clinical manifestation
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Biliary Atresia
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Hepatitis
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Hepatitis A
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Hepatitis B
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90% of newborns infected with hepatitis B from their
mothers develop chronic hepatitis and become
carriers
Hepatitis C
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33% of hepatitis A infections occur in children
Associated primarily with blood transfusions
Chronic hepatitis
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Cirrhosis
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Chronic liver diseases in children can
progress to cirrhosis, but it is infrequent
The complications for cirrhosis in children are
the same as in adults
Children may also experience growth failure,
nutritional deficits, and developmental delay
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Portal Hypertension
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Extrahepatic portal hypertension
Intrahepatic portal hypertension
Splenomegaly
Hepatic encephalopathy
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Wilson Disease
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Autosomal recessive defect of copper
metabolism; causes toxic levels of copper to
accumulate in the liver, brain, kidneys, and
corneas
Abnormalities
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Diminished biliary excretion
 Failure to insert copper in to ceruloplasmin
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