What is the best course of treatment for a 2-year-old with vomiting and diarrhea lasting 4 days?

Management of Vomiting and Diarrhea in a 2-Year-Old After 4 Days

The priority is immediate assessment of hydration status and initiation of oral rehydration therapy (ORT) with oral rehydration solution (ORS), which is the cornerstone of treatment for acute gastroenteritis in children and as effective as intravenous therapy for mild to moderate dehydration. 1, 2

Immediate Assessment

Evaluate the degree of dehydration by examining:

• Skin turgor (pinch test on abdomen or thigh) 1, 2
• Mucous membranes (dry vs. moist) 1, 2
• Mental status (alert vs. lethargic) 1, 2
• Capillary refill time (>2 seconds is abnormal) 3
• Presence or absence of tears when crying 4
• Urine output (decreased frequency or amount) 5
• Weight the child to establish baseline 1, 2

Categorize dehydration severity:

• Mild (3-5% fluid deficit): Slightly dry mucous membranes, normal mental status 1, 2
• Moderate (6-9% fluid deficit): Dry mucous membranes, decreased skin turgor, sunken eyes 1, 2
• Severe (≥10% fluid deficit): Signs of shock, lethargy, very prolonged capillary refill, no tears, no urine output 1, 2

Treatment Based on Dehydration Severity

For Mild Dehydration (Most Likely Scenario)

• Administer 50 mL/kg of ORS over 2-4 hours 1, 2
• For a 12 kg 2-year-old, this equals approximately 600 mL over 2-4 hours 1
• Use small, frequent volumes initially: Give 5-10 mL (1-2 teaspoons) every 1-2 minutes using a spoon or syringe, then gradually increase as tolerated 2, 4
• This slow administration technique is critical for vomiting children and prevents worsening of emesis 2, 4

For Moderate Dehydration

• Administer 100 mL/kg of ORS over 2-4 hours 1, 2
• For a 12 kg child, this equals approximately 1200 mL over 2-4 hours 1
• Same slow administration technique as above 2

For Severe Dehydration (Medical Emergency)

• Immediate intravenous rehydration required with Ringer's lactate or normal saline 1, 2
• Administer 20 mL/kg boluses until pulse, perfusion, and mental status normalize 1, 2
• This requires emergency department or hospital care 1, 5

Replace Ongoing Losses

During rehydration, continuously replace ongoing losses:

• 10 mL/kg of ORS for each watery stool 1, 2
• 2 mL/kg of ORS for each vomiting episode 1, 2
• For a 12 kg child: 120 mL per watery stool, 24 mL per vomit 1

Nutrition Management

Resume feeding immediately after rehydration is achieved (do NOT withhold food for 24 hours):

• Continue breastfeeding throughout if applicable 1, 2
• Resume age-appropriate diet during or immediately after rehydration 1
• Full-strength formula or regular foods are appropriate 1
• Early refeeding reduces illness duration and improves outcomes 1

Note on lactose: While a lactose-free diet may reduce diarrhea duration by 18 hours, it is not essential unless lactose intolerance is clearly demonstrated 1. The BRAT diet has limited supporting evidence 1.

Medication Considerations

What NOT to Give

Do NOT give loperamide or any antimotility drugs to this 2-year-old—these are contraindicated in all children under 18 years of age due to risk of serious adverse events including ileus, lethargy, and death (0.54% mortality in children <3 years) 1, 2

What MAY Be Considered

Ondansetron is NOT recommended for a 2-year-old because guidelines only support its use in children >4 years of age to facilitate oral rehydration when vomiting is severe 1. For this 2-year-old, rely on the slow ORS administration technique instead 2, 4.

Probiotics may be offered to reduce symptom severity and duration in immunocompetent children 1, 6

Reassessment

Reassess hydration status after 2-4 hours of rehydration:

• If rehydrated: transition to maintenance phase with ongoing loss replacement 1, 2
• If still dehydrated: reestimate fluid deficit and restart rehydration 1
• If worsening or unable to tolerate oral intake: consider IV rehydration 1, 5

Red Flags Requiring Immediate Medical Attention

• Bloody diarrhea (may require antimicrobial treatment) 2
• Severe dehydration with shock 2
• Intractable vomiting preventing successful oral rehydration 2
• High stool output (>10 mL/kg/hour) 2
• Signs of worsening despite appropriate ORT 2

Critical Pitfall to Avoid

Do NOT allow the thirsty child to drink large volumes of ORS rapidly (ad libitum), as this commonly worsens vomiting 2. The slow, frequent small-volume technique is essential for success, especially with vomiting present 2, 4.