What is the recommended assessment and management for a 12‑month‑old infant presenting with vomiting?

Approach to Vomiting in a 1-Year-Old

Begin by immediately assessing for red-flag features that require urgent intervention: bilious vomiting (surgical emergency until proven otherwise), bloody vomitus, severe dehydration (≥10% fluid deficit with prolonged skin tenting >2 seconds, cool extremities, lethargy), toxic appearance with fever, or altered mental status. 1, 2

Immediate Red-Flag Assessment

Any bilious (green) vomiting at 12 months of age is a surgical emergency until proven otherwise and requires immediate imaging and surgical consultation. 1, 3 Midgut volvulus remains a critical consideration even beyond the neonatal period and can present at any age. 1, 4

Additional red flags requiring urgent evaluation include: 1, 2, 5

• Bloody vomitus or "currant-jelly" stools (suggests intussusception, which peaks between 6-18 months)
• Severe dehydration with prolonged capillary refill, cool extremities, and lethargy
• Toxic appearance with high fever (consider sepsis, meningitis, urinary tract infection)
• Abdominal distension or palpable mass
• Altered mental status or inconsolable crying

Hydration Status Evaluation

Stratify dehydration severity clinically: 1

• Mild (3-5% deficit): Increased thirst, slightly dry mucous membranes
• Moderate (6-9% deficit): Loss of skin turgor, dry mucous membranes, decreased urine output
• Severe (≥10% deficit): Lethargy, prolonged skin tenting >2 seconds, cool extremities, reduced capillary refill—requires immediate IV fluid resuscitation

Clinical History Essentials

Document the following specific characteristics: 1, 2

• Vomitus appearance: Bilious (green), bloody, projectile, or non-bilious
• Stool pattern: Bloody, "currant-jelly," watery, or absent passage
• Associated symptoms: Fever, abdominal pain, irritability, lethargy
• Feeding pattern: Relationship to meals, volume tolerance
• Recent exposures: Daycare attendance (Giardia, Shigella risk), recent antibiotics (C. difficile risk), sick contacts

Physical Examination Focus

Perform a targeted examination before initiating therapy: 1, 2

• Vital signs: Temperature, heart rate, blood pressure, respiratory pattern
• Abdominal exam: Distension, tenderness, palpable masses (intussusception can present as a sausage-shaped mass in right upper quadrant), bowel sounds
• Hydration markers: Capillary refill, skin turgor, mucous membrane moisture, fontanelle (if still open)
• Hernial orifices and genitalia: Rule out incarcerated hernia

Diagnostic Imaging Pathways

For Non-Bilious Vomiting Without Red Flags

Imaging is generally NOT required if the child has non-bilious vomiting with normal weight gain, normal examination, and clinical features consistent with viral gastroenteritis. 1, 4

For Bilious Vomiting or Suspected Obstruction

Obtain an abdominal radiograph immediately as the first imaging study. 1 This can identify bowel obstruction patterns and guide further management. 6

For Suspected Intussusception

Ultrasound is the recommended initial imaging modality if clinical features suggest intussusception (crampy intermittent pain, "currant-jelly" stools, lethargy, palpable mass). 1 Intussusception is uncommon in the first 3 months but peaks between 6-18 months. 6

Laboratory Testing Indications

Obtain laboratory studies when: 1, 2

• Severe dehydration is present (electrolytes, blood gases, renal function)
• Bloody diarrhea accompanies vomiting (stool cultures)
• Recent antibiotic use (C. difficile testing)
• Toxic appearance with fever (complete blood count, blood cultures, urinalysis)
• Concern for metabolic disorder (glucose, electrolytes, ammonia)

Do NOT obtain routine laboratory screening in well-appearing children with uncomplicated viral gastroenteritis. 2

Management Based on Etiology

Viral Gastroenteritis (Most Common at 12 Months)

Oral rehydration therapy (ORT) is the cornerstone of treatment. 1, 4 Administer ORS in small, frequent volumes (5 mL every minute initially, using a spoon or syringe). 4 Replace each vomiting episode with approximately 10 mL/kg of ORS. 4

Begin early refeeding with age-appropriate diet once rehydrated—continue full-strength formula or regular foods immediately in amounts sufficient to satisfy energy requirements. 1, 4

Antimicrobials are NOT indicated for watery diarrhea and vomiting in this age group, as the condition is most often viral. 1

Ondansetron Use

Ondansetron (0.2 mg/kg oral, maximum 4 mg) may be considered ONLY if persistent vomiting prevents oral intake entirely. 4, 2 However, it should not replace proper fluid and electrolyte management and is not routinely indicated for uncomplicated viral gastroenteritis. 4

Critical Contraindications

Never use antidiarrheal agents (loperamide, kaolin-pectin) in children—they are contraindicated because they do not reduce symptoms and can cause severe abdominal distention, ileus, and death. 1

Common Pitfalls to Avoid

• Never dismiss bilious vomiting as "just gastroenteritis"—it requires immediate imaging and surgical evaluation. 1, 3
• Do not rely solely on plain radiographs to exclude malrotation—plain films miss up to 7% of malrotation cases; upper GI series is required for bilious vomiting with non-classic findings. 1
• Avoid focusing on antiemetics at the expense of proper hydration assessment and fluid therapy. 4
• Do not overlook non-GI causes: Urinary tract infections, otitis media, pneumonia, and meningitis can all present with vomiting in this age group. 1, 2

Return Precautions for Parents

Instruct caregivers to return immediately if: 4

• Vomiting becomes bilious (green) or bloody
• Vomiting becomes projectile
• Decreased urine output (fewer than 4 wet diapers in 24 hours)
• Lethargy, inconsolable crying, or altered mental status
• Abdominal distension or severe pain
• Signs of worsening dehydration