What is the best way to manage diarrhea in an infant?

Management of Diarrhea in Infants

The cornerstone of managing infant diarrhea is rapid oral rehydration therapy (ORT) with glucose-electrolyte solutions, followed immediately by resumption of age-appropriate feeding—this approach prevents dehydration-related morbidity and mortality while shortening the duration of illness. 1, 2

Immediate Assessment of Hydration Status

Begin by rapidly assessing the infant's degree of dehydration using these key clinical indicators:

• Weight loss is the most reliable indicator of dehydration severity when pre-illness weight is available 1
• Capillary refill time is the most reliable predictor when weight is unknown 2
• Additional critical signs include: altered mental status, sunken eyes, dry mucous membranes, absence of tears, prolonged skin turgor, and decreased urine output 3, 1, 4

Classify dehydration severity:

• Mild: 3-5% fluid deficit 3, 1
• Moderate: 6-9% fluid deficit 3, 1
• Severe: ≥10% fluid deficit with shock or near-shock 3, 1

Rehydration Protocol Based on Severity

Severe Dehydration (≥10% deficit)

This is a medical emergency requiring immediate IV intervention. 3, 2

• Administer 20 mL/kg boluses of Ringer's lactate or normal saline IV immediately 3, 2
• Repeat boluses until pulse, perfusion, and mental status normalize 3, 2
• Once circulation is restored and consciousness returns, transition to oral rehydration solution (ORS) for the remaining deficit 3, 2

Moderate Dehydration (6-9% deficit)

• Administer 100 mL/kg of ORS over 2-4 hours 3, 1
• Use small, frequent volumes initially (5 mL every 1-2 minutes via spoon or syringe), gradually increasing as tolerated 3, 1
• Consider nasogastric administration if oral intake is not tolerated 2

Mild Dehydration (3-5% deficit)

• Administer 50 mL/kg of ORS over 2-4 hours 3, 1
• Use the same small-volume, frequent administration technique 3, 1

No Dehydration

• Skip rehydration phase and proceed directly to maintenance therapy with ongoing loss replacement 3

Managing Concurrent Vomiting

Do not let vomiting deter you from oral rehydration—over 90% of vomiting infants can be successfully rehydrated orally. 3

• Administer 5 mL of ORS every 1-2 minutes using a spoon or syringe 3, 1
• Gradually increase volume as tolerated 3, 1
• Common pitfall: Allowing a thirsty infant to drink large volumes rapidly from a bottle will worsen vomiting—always use controlled, small-volume administration 3
• For persistent vomiting, consider continuous slow nasogastric infusion 3

Replacing Ongoing Losses

Throughout both rehydration and maintenance phases:

• Replace 10 mL/kg of ORS for each watery or loose stool 3, 1, 2
• Replace 2 mL/kg of ORS for each vomiting episode 3, 1, 2
• Continue replacement until diarrhea and vomiting resolve 1

Nutritional Management

Resume feeding immediately upon rehydration—there is no justification for "bowel rest." 2

Breastfed Infants

• Continue breastfeeding on demand throughout the entire diarrheal episode without interruption 1, 2
• Breastfeeding reduces severity and duration of diarrhea 5

Formula-Fed Infants

• Resume full-strength formula immediately upon rehydration 1
• Use regular formula; lactose-free formulas have no demonstrated benefit 5

Older Infants (>6 months)

• Resume age-appropriate solid foods immediately, including starches, cereals, yogurt, fruits, and vegetables 1, 2
• Avoid foods high in simple sugars and fats during acute phase 2

Zinc Supplementation

• Administer oral zinc supplementation to infants 6 months to 5 years of age 1
• Zinc reduces duration of diarrhea, particularly in malnourished infants 1

Reassessment and Monitoring

• Reassess hydration status after 2-4 hours of rehydration 3, 1, 2
• If rehydrated, transition to maintenance phase with ongoing loss replacement 2
• If still dehydrated, reestimate fluid deficit and restart rehydration 3

Instruct caregivers to return immediately if:

• Persistent watery stools continue 2
• Intractable vomiting develops 3, 2
• Decreased urine output occurs 3
• Infant becomes irritable, lethargic, or condition worsens 3, 2
• Bloody diarrhea appears 2
• High stool output (>10 mL/kg/hour) persists 2

Critical Medications to AVOID

Antimotility drugs (loperamide) are absolutely contraindicated in all infants and children under 18 years of age due to risks of respiratory depression, cardiac arrest, and serious cardiac adverse reactions. 1, 2, 6

• Postmarketing cases of cardiac arrest, syncope, and respiratory depression have been reported in pediatric patients under 2 years 6
• Antiemetics (ondansetron) are contraindicated in infants under 4 years of age 1
• Do not use cola drinks or soft drinks for rehydration—they contain inadequate sodium and excessive osmolality that worsens diarrhea 2, 5

When to Consider Antibiotics

Antibiotics are NOT routinely indicated for acute watery diarrhea. 3, 2

Consider antimicrobial therapy only when:

• Bloody diarrhea (dysentery) is present 3, 1
• Watery diarrhea persists for more than 5 days 3, 1
• Stool cultures indicate a specific pathogen requiring treatment 2
• High fever accompanies diarrhea 1

Home Management and Prevention

• Parents should keep ORS sachets at home and begin administration at the first sign of diarrhea 3, 5
• Increase fluid intake immediately when diarrhea begins 3, 5
• Emphasize hand hygiene after diaper changes, before food preparation, and before eating 1
• Provide written instructions with ORS dispensing 5