Pediatric Gastroenterology

Question 1

necrotizing enterocolitis (NEC) - overview

Answer 1

*ischemic necrosis of the intestinal mucosa
*associated with inflammation, invasion of enteric gas-forming organisms, and dissection of gas into the bowel wall and portal venous system
*most common GI emergency in newborn infant

Question 2

necrotizing enterocolitis - pathogenesis

Answer 2

*multifactorial process:
-increased susceptibility (immature intestinal tract and immune system)
-microbial dysbiosis (increased growth of pathogenic bacteria)
-exaggerated host inflammatory response (release of cytokines and chemokines)

Question 3

necrotizing enterocolitis - risk factors

Answer 3

*prematurity
*microbial bowel overgrowth
*milk feeding (human milk is protective)
*medications (hyperosmolar or acid suppression)
*circulatory instability
*primary infection

Question 4

necrotizing enterocolitis - clinical features

Answer 4

*nonspecific early signs/symptoms: apnea, bradycardia, temperature instability
*abdominal distension, tenderness
*increased gastric residuals
*emesis (typically bilious), hematochezia
*peritonitis, shock
*30% bacteremia

Question 5

necrotizing enterocolitis - management

Answer 5

*NPO
*nasogastric tube placement
*antimicrobial therapy
*surgery for pneumoperitoneum

Question 5

intussusception - overview

Answer 5

*most common cause of intestinal obstruction and abdominal emergency in children
*often occurs between 3 months and 6 years (majority < 2 years)
*part of the intestine slides into another part of the intestine (telescoping)
*slight male predominance
*increased risk of recurrence

Question 6

intussusception - pathogenesis

Answer 6

*75% idiopathic (possible viral infection or other enteric infection)
*25% due to presence of lead point such as Meckel’s diverticulum, polyp, tumor, etc

Question 7

intussusception - clinical features

Answer 7

*intermittent abdominal pain (every 15-20 min):
-inconsolable crying in infants
*“currant jelly” stool
*abdominal distension
*vomiting (possibly bilious)
*lethargy
*sausage-shaped abdominal mass on PE

Question 8

intussusception - diagnosis

Answer 8

*ultrasound: classic “bullseye” mass lesion or “target sign”
*barium enema

Question 9

intussusception - management

Answer 9

*non-operative reduction:
-using hydrostatic or pneumatic pressure via enema
-high success rate with fluoroscopic guidance
-only in stable patient without signs of perforation

*surgical reduction:
-ill patient, peritonitis or perforation, unsuccessful non-operative reduction; identified lead point that requires surgery

Question 10

cystic fibrosis - overview

Answer 10

*abnormal chloride transport caused by mutations in the CFTR gene (CF transmembrane conductance regulator)
*results in abnormally thick mucous and secretions in lumens of the body: lungs, gut, pancreas, biliary tract
*complications less severe since introduction of CFTR modulators

Question 11

cystic fibrosis - GI manifestations

Answer 11

*intestinal: GERD, meconium ileus, DISTAL INTESTINAL OBSTRUCTION SYNDROME (DIOS), constipation, intussusception

*pancreatic: pancreatic insufficiency, failure to thrive, malabsorption of fat-soluble vitamins (ADEK), chronic pancreatitis

*hepatobiliary: cirrhosis, cholelithiasis, steatosis, portal hypertension

Question 12

distal intestinal obstruction syndrome (DIOS) - overview

Answer 12

*acute complete or partial obstruction of the terminal ileum and colon by inspissated fecal material
*common in cystic fibrosis patients
*risk factors: severe CF, pancreatic insufficiency, fat malabsorption, dehydration

Question 13

distal intestinal obstruction syndrome (DIOS) - clinical features

Answer 13

*RLQ abdominal pain (acute or intermittent)
*classic triad: RLQ mass, abdominal pain and distention, radiograph showing accumulation of stool in distal small intestine and right colon

Question 14

distal intestinal obstruction syndrome (DIOS) - management

Answer 14

*correct fluid and electrolyte abnormalities
*oral laxatives via NG lavage
*enemas (if vomiting or complete obstruction)
*surgery (if unresponsive to above or development of ischemia)

Question 15

cystic fibrosis-related pancreatic disease

Answer 15

1. pancreatic insufficiency:
   -most common GI manifestation of CF
   -steatorrhea, malnutrition, fat-soluble vitamin malabsorption (ADEK)
2. pancreatitis
   -15-20% of patients with pancreatic SUFFICIENCY
   -“mild” phenotypes
   -exacerbated by alcohol or smoking

Question 16

cystic fibrosis-related liver disease

Answer 16

*ranges from asymptomatic elevated liver enzymes to portal HTN and cirrhosis
*decreased flow and increased viscosity of bile
*requires annual screening with labs and radiographic imaging
*common liver diseases:
-characteristic lesion = focal biliary cirrhosis
-neonatal cholestasis
-hepatic steatosis
-microgallbladder
-cholelithiasis

Question 17

cystic fibrosis-related liver disease - management

Answer 17

*optimize nutrition
*CFTR modulators
*risk reduction (viral hepatitis vaccination, avoid alcohol and hepatotoxic meds)
*ursodeoxycholic acid
*management of specific complications
*liver transplant (often liver-lung)

Question 18

cyclic vomiting syndrome - epidemiology

Answer 18

*prevalence in children ~2%
*average age at diagnosis = 9 years
*more common in females
*associated with history of migraines
*unknown pathogenesis

Question 19

cyclic vomiting syndrome - diagnostic criteria

Answer 19

*2+ periods of intense, unremitting nausea and paroxysmal vomiting, lasting hours to days within a 6-month period
*episodes are stereotypical in each patient
*episodes are separated by weeks to months with return to baseline health between episodes
*symptoms unattributable to another medical condition after appropriate evaluation

Question 20

cyclic vomiting syndrome - clinical features

Answer 20

*specific stereotypical pattern per each patient (typically lasts 2 days; mean 12 cycles per year)
*vomiting: 6-8 times/hr at peak (often at night or early morning)
*lethargy/pallor, fever
*abdominal pain, retching, anorexia, nausea
*migraine-like sx
*use of hot showers to abate nausea

Question 21

cyclic vomiting syndrome - triggers

Answer 21

*infection
*psychological stress
*dietary
*menstrual
*cannabis withdrawal

Question 22

cyclic vomiting syndrome - evaluation

Answer 22

*exclusion of other causes of vomiting
*if no warning signs: imaging, labs, trial of prophylactic therapy (trying to rule out other diagnoses)

*warning signs:
-GI: unilateral abdominal pain, weight loss, hematemesis, bilious emesis
-metabolic: episode triggered by fasting or high protein meal, AG acidosis
*neuro: severe headache, AMS, focal neuro deficit

Question 23

cyclic vomiting syndrome - management

Answer 23

*lifestyle interventions
-avoid known triggers
-management of comorbidities

*supportive care (during an episode) - IV hydration, proper environment, antiemetics
*abortive meds = ondansetron
*prophylactic meds: cyproheptadine (< 5) and amitriptyline (> 5)

Question 24

cyclic vomiting syndrome - prognosis

Answer 24

*goal of tx is to abort episodes, achieve remission, then manage recovery
*many children outgrow CVS by teenage years
*75% develop migraine headaches by 18 yo
*some develop abdominal migraines

Question 25

chronic abdominal pain in children - epidemiology

Answer 25

*2-4% of visits to general pediatrician
*10-20% of children
*peaks at 4-6 years of age then early teen years
*up to 20% report pain significant enough to restrict activity

Question 26

examples of functional GI diseases of childhood presenting with abdominal pain

Answer 26

*functional dyspepsia (pain or discomfort in epigastric region)
*irritable bowel syndrome (chronic abdominal pain with altered bowel habits)
*abdominal migraine (recurrent episodes for at least 6 months with associated migraine symptoms)
*functional abdominal pain (pain > 2 months and do not meet criteria for above disorders)

Question 27

management of functional GI disorders

Answer 27

*rule out organic etiologies
*goal to to return to normal function, rather than elimination of pain
*multidisciplinary approach
*therapeutic clinical-patient/family relationship
*patient/family education
*return to school
*behavioral modification - avoidance of triggers
*symptomatic management