What are common pediatric gastro cases for a 1st year pediatrics (pedia) resident to encounter?

Common Pediatric Gastroenterology Cases for First-Year Pediatric Residents

Most Frequently Encountered Conditions

First-year pediatric residents will most commonly encounter gastroesophageal reflux disease (GERD), acute gastroenteritis, constipation, recurrent abdominal pain, and feeding-related problems including food intolerances. 1, 2

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1. Gastroesophageal Reflux Disease (GERD)

Age-Specific Presentations

Infants (Under 12 Months)

• Physiologic reflux peaks at 4 months of age, affecting approximately 50% of infants, then resolves in 90-95% by 12 months. 3
• The "happy spitter" with effortless, painless regurgitation and normal growth requires only parental reassurance—avoid overuse of medications in this population. 4
• Pathologic GERD presents with irritability, feeding refusal, poor weight gain, sleep disturbance, and respiratory symptoms (coughing, choking, wheezing). 5

Children (1-11 Years)

• Symptoms mirror adults more closely: abdominal pain, recurrent vomiting, and feeding difficulties. 5
• Heartburn becomes more common as children approach adolescence. 6

Adolescents (12-17 Years)

• Present with adult-like symptoms: predominantly heartburn and regurgitation. 5
• Stress and anxiety can trigger and worsen GERD symptoms through the brain-gut axis. 6

Critical Warning Signs Requiring Immediate Investigation

Stop and investigate beyond simple GERD when you see: 5

• Bilious vomiting or consistently forceful/projectile vomiting
• Gastrointestinal bleeding (hematemesis or melena)
• Poor weight gain or weight loss
• Fever, lethargy, or systemic symptoms
• Abdominal tenderness or distension
• Neurologic signs (bulging fontanelle, macro/microcephaly, seizures)
• Hepatosplenomegaly

Diagnostic Approach

For uncomplicated cases without warning signs, history and physical examination alone are sufficient to diagnose and initiate treatment—avoid unnecessary testing. 5

Reserve diagnostic studies for: 5

• Presence of warning signs
• Diagnostic uncertainty
• Treatment failure after 4-8 weeks
• Suspected complications (esophagitis, stricture)

Specific testing modalities: 4

• Upper endoscopy with biopsy: Indicated for failed pharmacologic therapy, unexplained anemia, recurrent pneumonia, or hematemesis
• pH monitoring or combined pH/impedance: For correlating symptoms with reflux episodes
• Upper GI series: Only to rule out anatomic abnormalities, NOT to diagnose GERD

Management Algorithm

Step 1: Lifestyle Modifications (All Ages) 4

For Infants:

• Trial 2-4 week maternal exclusion diet (eliminate milk and egg) in breastfed infants 4
• Switch to extensively hydrolyzed or amino acid-based formula in formula-fed infants 4
• Reduce feeding volume while increasing frequency 4
• Upright positioning after feeds 3
• Avoid overfeeding and ensure frequent burping 3

For Older Children:

• Avoid trigger foods (caffeine, chocolate, acidic foods, fatty foods)
• Weight loss if obese
• Avoid eating 2-3 hours before bedtime
• Head of bed elevation

Step 2: Pharmacologic Therapy (If Lifestyle Changes Fail) 4, 7

Acid Suppression:

• PPIs are first-line for children ≥1 year with documented GERD. 4
• Lansoprazole dosing (FDA-approved): 7
  • Ages 1-11 years: 15 mg daily if ≤30 kg; 30 mg daily if >30 kg
  • Ages 12-17 years: 15 mg daily for non-erosive GERD; 30 mg daily for erosive esophagitis
  • Duration: 8-12 weeks maximum
• Empirical PPI trial for 2 weeks in older children with heartburn; if improves, continue for 8-12 weeks total. 4

Critical Pitfall:

• Lansoprazole is NOT effective and NOT indicated for infants <1 year with symptomatic GERD. 7
• Avoid acid suppression in "happy spitters" with physiologic reflux—may increase risk of pneumonia, gastroenteritis, and candidemia. 3, 5

Step 3: Reassess if No Improvement 4

• If PPI therapy fails, question the diagnosis—consider alternative conditions:
  • Eosinophilic esophagitis
  • Cyclic vomiting syndrome
  • Rumination syndrome
  • Gastroparesis
  • Milk protein allergy

Step 4: Surgical Referral (Rare) 4

• Reserved for children with intractable symptoms unresponsive to medical therapy
• Children at severe risk of aspiration
• Fundoplication is the most common procedure

High-Risk Populations Requiring Aggressive Management

These children need early specialist involvement: 5

• Neurologic impairment (cerebral palsy)—chronic, severe GERD that doesn't spontaneously resolve
• Obesity
• History of esophageal atresia repair
• Chronic respiratory disorders

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2. Acute Gastroenteritis (AGE)

Clinical Presentation

• Sudden onset of diarrhea (≥3 loose stools in 24 hours) with or without vomiting 8
• Symptoms typically last <7 days 8
• Most commonly viral etiology in developed countries 8

Assessment of Dehydration Severity

Use clinical dehydration scales to guide management: 8

• Mild (3-5% loss): Slightly dry mucous membranes, normal vital signs
• Moderate (6-9% loss): Dry mucous membranes, decreased tears, sunken eyes, decreased skin turgor
• Severe (≥10% loss): Markedly sunken eyes/fontanelle, absent tears, tenting skin, altered mental status, weak pulse

Management Algorithm

Step 1: Oral Rehydration Therapy (ORT) is First-Line 8

• ORT remains the best means of rehydrating children with mild-to-moderate dehydration 8
• Use commercially available oral rehydration solutions (not sports drinks or juice)
• Give 50-100 mL/kg over 2-4 hours for mild-moderate dehydration

Step 2: Ondansetron for Persistent Vomiting 8

• Ondansetron is safe and effective as an adjunct to help children with persistent vomiting tolerate ORT. 8
• Reduces need for IV hydration and hospitalization

Step 3: Early Refeeding

• Resume age-appropriate diet as soon as rehydration is achieved 8
• No need for BRAT diet or prolonged dietary restrictions

Critical Pitfall:

• Inaccurate assessment or delayed treatment increases risk for invasive interventions and hospitalization 8

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3. Chronic Constipation

Clinical Features

• Infrequent bowel movements, hard stools, painful defecation 1
• May present with fecal soiling/encopresis
• Abdominal pain that improves with defecation

Management Approach

• Behavioral interventions: scheduled toilet time, positive reinforcement
• Dietary modifications: increased fiber and fluid intake
• Pharmacologic disimpaction followed by maintenance therapy with osmotic laxatives (polyethylene glycol)

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4. Recurrent Abdominal Pain

Presentation

• Episodic or continuous abdominal pain occurring ≥3 times over ≥3 months 1
• Often functional (no organic cause identified) 2

Diagnostic Categories

Functional gastrointestinal disorders are most common: 2

• Functional dyspepsia
• Irritable bowel syndrome
• Abdominal migraine
• Functional abdominal pain

Red flags requiring investigation:

• Weight loss or growth failure
• Persistent vomiting
• Gastrointestinal bleeding
• Chronic diarrhea
• Fever
• Arthritis or rash
• Family history of inflammatory bowel disease or celiac disease

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5. Food Intolerances and Celiac Disease

Milk Protein Allergy

• Can mimic GERD in infants 4
• Trial elimination diet for 2-4 weeks in suspected cases 4

Celiac Disease

• Presents with chronic diarrhea, failure to thrive, abdominal distension 1
• Screen with tissue transglutaminase IgA and total IgA
• Confirm with small bowel biopsy

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6. Inflammatory Bowel Disease (IBD)

Pediatric-Specific Features

Pediatric-onset IBD has distinct phenotypic differences from adult-onset disease: 4

• More extensive disease at presentation
• Ulcerative colitis in children: 90% have extensive colitis vs. only 10% with left-sided disease 4
• Less severe architectural abnormalities initially 4
• Rectal sparing occurs in 30% of pediatric UC (uncommon in adults) 4

Diagnostic Gold Standard

• Endoscopic evaluation of upper AND lower GI tracts with mucosal biopsies 4
• Upper GI inflammation occurs in up to 75% of children with UC (not diagnostic for Crohn's) 4

Key Diagnostic Pitfall

• Basal plasmocytosis is less common in children (58%) than adults, but remains an early feature 4
• Children <10 years may show less architectural distortion than adolescents or adults 4

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Key Takeaways for First-Year Residents

1. GERD is the most common GI complaint—distinguish physiologic reflux from pathologic GERD and avoid overtreatment of "happy spitters." 4, 3

2. Master clinical dehydration assessment for AGE—ORT with ondansetron for vomiting prevents most hospitalizations. 8

3. Always investigate warning signs (bilious vomiting, GI bleeding, poor growth, systemic symptoms) before attributing symptoms to functional disorders. 5

4. Pediatric IBD presents differently than adult IBD—more extensive disease with atypical features like rectal sparing. 4

5. Milk protein allergy commonly mimics GERD in infants—trial elimination before escalating to acid suppression. 4