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🩺 Gastrointestinal Disorders in Children — Comprehensive Notes

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1. VOMITING IN CHILDREN

Definition

• The vomiting center in the reticular formation of the medulla
• The chemoreceptor trigger zone (CTZ) underlying the floor of the fourth ventricle

Distinguish vomiting from:

• Regurgitation – effortless return of small amounts of food/fluid (passive, no nausea)
• Rumination – voluntary regurgitation, re-chewing, and re-swallowing
• Retching – rhythmic respiratory movements without expulsion

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Causes of Vomiting (Age-Specific)

Newborn

Infants (1–12 months)

• Gastroesophageal reflux (GERD)
• Pyloric stenosis (peaks 3–6 weeks)
• Intussusception
• Overfeeding
• Metabolic disorders
• CNS causes (raised ICP)
• Infections (UTI, otitis media, meningitis)

Toddlers & Older Children

• Gastroenteritis (most common) — viral (rotavirus, norovirus), bacterial
• Appendicitis
• Intussusception
• Intestinal obstruction
• Peptic ulcer disease / GERD
• Cyclic vomiting syndrome
• Medications / toxins / poisoning
• Diabetic ketoacidosis (DKA)
• Raised intracranial pressure (head injury, meningitis, tumor)
• Renal disease (UTI, nephrolithiasis)
• Psychogenic vomiting

Key point: Bilious or bloody vomitus, hematochezia, or significant abdominal pain should trigger concern for a surgical or serious non-GI diagnosis. Isolated vomiting should NOT automatically be diagnosed as gastroenteritis.

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Dangerous Signs Requiring Urgent Referral/Hospitalization

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Principles of Management of Vomiting in Children

1. Assess and Classify Severity

• Determine degree of dehydration: none → mild → moderate → severe
• Signs of severe dehydration: markedly decreased urine output, sunken eyes/fontanelle, absent tears, dry mucous membranes, prolonged CRT >3 sec, tachycardia, hypotension, lethargy

2. Oral Rehydration Therapy (ORT) — First Line

• Use WHO/UNICEF Oral Rehydration Solution (ORS) (75 mEq/L sodium, 75 mmol/L glucose)
• For moderate dehydration: give 50–100 mL/kg ORS over 4 hours, plus 10 mL/kg per stool and 2 mL/kg per emesis for ongoing losses
• Start with small volumes: 5 mL every 2–5 minutes, increase as tolerated
• General rule: ~30 mL/kg/hour
• Do NOT withhold breastfeeding

3. Nasogastric Rehydration

• If oral rehydration not feasible, NGT route is as effective as IV and more cost-effective
• Provides steady-rate rehydration

4. IV Rehydration

• For severe dehydration or shock
• Isotonic saline or Ringer's lactate; 20 mL/kg bolus, repeat as needed
• Begin ORT when perfusion and mental status normalize

5. Antiemetics

• Ondansetron (5-HT₃ antagonist): 0.15 mg/kg/dose PO — adjunct to ORT in persistent vomiting, single dose
• Avoid dopamine receptor agonists (promethazine, metoclopramide, prochlorperazine, droperidol) — risk of respiratory depression, extrapyramidal reactions; promethazine contraindicated under 2 years

6. Refeeding / Diet

• Resume age-appropriate diet as soon as fluid deficit replaced
• Do NOT withhold feeds for >4 hours
• Full-strength formula/regular diet immediately after rehydration → promotes weight gain
• BRAT diet (banana, rice, applesauce, toast) is no longer recommended — unnecessarily restrictive
• Low-fat diets discouraged (fats are important calorie source)

7. Treat the Underlying Cause

• Surgical consult for obstructive/bilious vomiting
• Antibiotics for bacterial infections if indicated
• Manage metabolic disorders appropriately

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2. HEARTBURN (GASTROESOPHAGEAL REFLUX / GERD)

Definition

• GER (physiological): passage of gastric contents into the esophagus — normal in infants
• GERD (pathological): GER causing troublesome symptoms or complications

Causes / Predisposing Factors

Clinical Features

• Regurgitation/spitting up (most common, usually physiological)
• Irritability, back-arching (Sandifer syndrome)
• Poor feeding, food refusal
• Failure to thrive (severe cases)
• Apnea, choking, cyanosis (alarming symptoms)

• Heartburn — burning sensation behind sternum, worse after meals, bending, lying down
• Regurgitation of sour/bitter fluid
• Epigastric pain
• Dysphagia / odynophagia
• Water brash (excess salivation)
• Dental erosion (acid in mouth)
• Chronic cough, hoarseness, wheezing (extraesophageal manifestations)
• Nocturnal symptoms (awakening)

Management

Conservative (First-Line)

• Lifestyle modifications:
  • Avoid trigger foods (fatty, spicy, acidic foods, caffeine, carbonated drinks, chocolate, mint)
  • Elevate head of bed 30°
  • Smaller, more frequent meals
  • Weight loss if obese
  • Avoid eating 2–3 hours before lying down
  • In infants: thickened feeds, smaller more frequent feedings, prone positioning after feeds (supervised only)

Pharmacological

Surgical

• Nissen fundoplication: for refractory GERD, complications (Barrett's esophagus, severe esophagitis, failure to thrive despite maximal medical therapy)
• Especially considered in neurologically impaired children

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3. CONSTIPATION IN CHILDREN

Definition

• ≤2 defecations per week
• ≥1 episode of fecal incontinence/week (after toilet training)
• History of retentive posturing or excessive stool retention
• History of painful or hard bowel movements
• Large fecal mass in the rectum
• Large-diameter stools that may obstruct the toilet

Causes

Red flags for organic cause: onset from birth, failure to pass meconium in first 48 hours, ribbon stools, abdominal distension, abnormal anal position, bloody diarrhea, failure to thrive

Clinical Features

• Infrequent or absent stools
• Hard, pellet-like or very large stools
• Pain on defecation — child may withhold stool → vicious cycle
• Soiling/encopresis: overflow diarrhea around impacted stool
• Abdominal pain and bloating
• Poor appetite, nausea
• Palpable colonic mass (scybala) in left lower quadrant
• Palpable stool on rectal examination (distended rectum)
• Behaviour changes: irritability, withdrawal

Management

1. Disimpaction (if fecal impaction present)

• Oral: Polyethylene glycol (PEG/Macrogol) — high-dose, 1–1.5 g/kg/day for 3–6 days
• Rectal: Enemas (sodium phosphate, normal saline), suppositories (glycerine)

2. Maintenance Therapy

• PEG 3350 (Macrogol): 0.2–0.8 g/kg/day — first-line maintenance
• Lactulose: osmotic laxative — second-line; sweetish taste acceptable to children
• Senna/bisacodyl: stimulant laxatives — for short-term use
• Mineral oil: lubricant (not in infants <1 year — aspiration risk)

3. Dietary Modifications

• Increase fiber (fruits, vegetables, whole grains)
• Increase fluid intake
• Reduce excess cow's milk

4. Behavioural / Toilet Training

• Regular toilet routine after meals (exploit gastrocolic reflex)
• Footstool for proper defecation posture
• Positive reinforcement charts
• Address fear/anxiety around defecation

5. Treat Underlying Cause

• Hirschsprung's disease → surgical resection of aganglionic bowel
• Hypothyroidism → levothyroxine

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4. DYSPEPSIA IN CHILDREN

Definition

1. Postprandial fullness
2. Early satiation
3. Epigastric pain or burning not associated with defecation

Causes

Clinical Features

• Epigastric pain or burning — often post-prandial
• Early satiety (feeling full quickly)
• Postprandial fullness / bloating
• Nausea (with or without vomiting)
• Belching / excessive gas
• Anorexia, weight loss (in organic disease)
• No relief with defecation (distinguishes from IBS)
• Alarm features (rare in functional): hematemesis, unexplained weight loss, progressive dysphagia, persistent vomiting, family history of GI malignancy → warrants investigation

Management

1. Lifestyle

• Avoid trigger foods (fatty, spicy, acidic, caffeine, carbonated drinks)
• Smaller, more frequent meals
• Eat slowly
• Reduce stress/anxiety

2. Pharmacological

3. Psychological

• Cognitive behavioural therapy (CBT)
• Relaxation techniques, biofeedback
• Address school/social stressors

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5. ACUTE GASTROENTERITIS IN CHILDREN

Definition

Note: The clinical diagnosis of gastroenteritis requires the presence of diarrhea. Isolated vomiting should NOT be diagnosed as acute gastroenteritis.

Causes

Viral (most common, ~70–80%)

Bacterial (~10–20%)

Parasitic

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Clinical Features of Acute Gastroenteritis

General

• Acute onset of diarrhea (loose/watery stools ≥3/day)
• Nausea and vomiting (may precede diarrhea)
• Abdominal cramping/pain
• Fever (more common in bacterial/rotavirus infections)
• Anorexia, malaise

Dehydration Assessment (Critical Component)

Bacterial vs Viral Gastroenteritis

Specific Pathogens' Patterns

• Rotavirus: 3–8 day illness; watery diarrhea, vomiting, fever in first 24–48 hrs; more severe in infants
• Norovirus: Explosive vomiting, watery diarrhea, myalgia; resolves in 1–3 days
• Shigella: High fever, bloody mucoid stools, tenesmus, severe abdominal cramps
• STEC O157:H7: Bloody diarrhea without fever → risk of hemolytic uremic syndrome (HUS)
• Cholera: Profuse rice-water stools, rapid severe dehydration, little or no fever

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Management of Acute Gastroenteritis in Children

Step 1: Assess Dehydration

• Degree and type of dehydration determines treatment route and urgency

Step 2: Oral Rehydration Therapy (ORT) — Gold Standard

• WHO low-osmolarity ORS (245 mOsmol/L): 75 mEq/L Na, 65 mEq/L Cl, 20 mEq/L K, 75 mmol/L glucose
• No dehydration: increase fluids (ORS/breast milk); continue normal diet
• Mild–Moderate dehydration: 50–100 mL/kg ORS over 4 hours + replacement of ongoing losses (10 mL/kg/stool; 2 mL/kg/vomit)
• Start with 5 mL every 2–5 min; increase gradually
• Continue breastfeeding throughout

Step 3: IV Rehydration (Severe Dehydration/Shock)

• 0.9% NaCl or Ringer's Lactate: 20 mL/kg IV bolus; repeat as needed
• Correct electrolyte abnormalities
• Transition to ORT when child is alert and stable

Step 4: Refeeding

• Resume age-appropriate diet as soon as rehydrated
• No prolonged fasting (>4 hours not recommended in dehydrated; none in non-dehydrated)
• Lactose-free formula in hospitalized patients with lactose intolerance
• BRAT diet no longer recommended

Step 5: Antiemetics

• Ondansetron 0.15 mg/kg PO (single dose) — adjunct to ORT for persistent vomiting
• Avoid promethazine, metoclopramide, prochlorperazine

Step 6: Antidiarrheal Medications

• Generally NOT recommended in children (safety concerns, lack of efficacy)
• Zinc supplementation (10–20 mg/day × 10–14 days): shown to reduce duration and severity of diarrhea, especially in developing countries (WHO recommendation)
• Probiotics: some evidence for reducing duration (Lactobacillus GG, Saccharomyces boulardii); not universally recommended

Step 7: Antibiotics

• Generally NOT indicated for viral or mild-moderate bacterial diarrhea
• Indications for antibiotics:
  • Shigella: azithromycin or ceftriaxone
  • Giardia: metronidazole or tinidazole
  • Cryptosporidium (immunocompromised): nitazoxanide
  • Cholera: azithromycin or doxycycline
  • C. difficile: metronidazole (mild-moderate) or vancomycin (severe)
  • Severe Salmonella/bacteremia: ceftriaxone
• Avoid antibiotics in STEC O157:H7 — increases HUS risk

Step 8: Prevention

• Hand hygiene (soap and water — most important)
• Rotavirus vaccination (RotaTeq, Rotarix) — dramatically reduces severe gastroenteritis
• Safe food handling, clean water
• Proper hygiene in child care settings

Hospitalization Indications

• Severe dehydration or clinical shock
• Unable to maintain oral hydration (persistent vomiting)
• Altered mental status / seizures
• Suspected surgical cause
• Failure of ORT
• Significant electrolyte disturbances
• Age <3 months or at-risk populations
• Bloody diarrhea with systemic toxicity

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6. INSPECTION OF THE ORAL CAVITY

a) Tongue

b) Tongue Cover (Coating)

c) Angular Stomatitis (Angular Cheilitis)

• Definition: Inflammation, cracking, and soreness at the corners (angles) of the mouth
• Causes:
  • Nutritional deficiencies: Iron deficiency anemia, Riboflavin (B₂) deficiency, Niacin (B₃) deficiency, Pyridoxine (B₆) deficiency, Zinc deficiency
  • Infection: Candida albicans (most common infectious cause), Staphylococcus aureus, Streptococcus
  • Drooling (in children with neurological impairment)
  • Ill-fitting dentures (older children with dental problems)
  • Inflammatory bowel disease (Crohn's disease)
  • Immunodeficiency (HIV)
• Appearance: Erythema, fissuring, scaling, ulceration at angles of mouth; may be unilateral or bilateral
• Management: Treat underlying cause; topical antifungal (clotrimazole/miconazole) if fungal; address nutritional deficiencies

d) Mouth Ulcers (Oral Ulcerations)

e) Rashes / Lesions in the Oral Cavity

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7. ABDOMINAL INSPECTION FROM A DISTANCE

a) Size, Shape, and Contour

b) Peristaltic Waves

• Visible peristalsis is ABNORMAL
• Normally not visible through abdominal wall
• Gastric peristalsis (wave from left to right across upper abdomen): pyloric stenosis, gastric outlet obstruction
• Intestinal peristalsis (ladder-pattern): intestinal obstruction
• Better seen in thin/malnourished children or infants

c) Visible Masses

d) Caput Medusae

• Definition: Visibly dilated, tortuous periumbilical veins that radiate outward from the umbilicus, resembling the head of Medusa
• Cause: Portal hypertension → blood diverted through patent paraumbilical veins (recanalization of the umbilical vein) → into superficial epigastric and lateral thoracic veins
• Blood flows away from the umbilicus in caput medusae (distinguishes from IVC obstruction where flow is upward in flanks)
• Causes in children: Liver cirrhosis (biliary atresia, viral hepatitis, Wilson's disease, alpha-1 antitrypsin deficiency), portal vein thrombosis, Budd-Chiari syndrome
• Associated findings: ascites, splenomegaly, jaundice, palmar erythema

e) Stomas

• Inspect stoma for: color (should be pink/red), output, prolapse, retraction, stenosis, peristomal skin condition

f) Striae

• Definition: Linear marks on the skin caused by rapid stretching of the dermis (collagen disruption)
• Types:
  • Striae rubra (red/purple): active/recent
  • Striae alba (white/silver): older, permanent
• Causes in children:

  Cause	Notes
  Rapid weight gain / obesity	Abdominal, thighs, breasts
  Cushing's syndrome	Wide (>1 cm), purple striae; particularly on abdomen, thighs, axillae — hallmark finding
  Adolescent growth spurt	Back, thighs, hips — physiological
  Long-term topical/systemic corticosteroid use	Can mimic Cushing's
  Marfan syndrome	Pectoral girdle, flanks
  Pregnancy (adolescents)	Abdomen

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8. DETERMINATION OF CLINICAL SIGNS OF PATHOLOGICAL SYNDROMES

Key Abdominal Pathological Signs and Their Significance

Dehydration Syndrome Signs (see table above in AGE section)

Signs of Malnutrition

• Wasted buttocks, prominent ribs
• Edema (kwashiorkor): pitting edema, "flaky paint" dermatosis, moon face, parotid enlargement
• Marasmus: severe wasting, skin-and-bones appearance, preserved alertness initially
• Angular stomatitis, glossitis (nutritional deficiencies)
• Distended abdomen in kwashiorkor

Signs of Liver Disease / Portal Hypertension

• Jaundice, scleral icterus
• Caput medusae
• Ascites (shifting dullness, fluid thrill)
• Splenomegaly
• Spider angiomata
• Palmar erythema
• Clubbing
• Leukonychia

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Summary Table: Key Pediatric GI Conditions

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