Fluid Replacement for Ongoing Stool Losses in Children
For ongoing stool replacement in pediatric patients, administer 10 mL/kg of oral rehydration solution (ORS) for each watery or loose stool, with weight-based volume adjustments: 60-120 mL per stool for children <10 kg body weight (up to ~500 mL/day), and 120-240 mL per stool for children >10 kg body weight (up to ~1 L/day). 1, 2
Weight-Based Replacement Algorithm
Children Under 10 kg Body Weight
- Administer 60-120 mL of ORS per diarrheal stool 1
- Maximum daily replacement: approximately 500 mL/day 1
- This translates to approximately 10 mL/kg per stool 2, 3
Children Over 10 kg Body Weight
- Administer 120-240 mL of ORS per diarrheal stool 1
- Maximum daily replacement: approximately 1 L/day 1
- This maintains the 10 mL/kg per stool guideline 2, 3
Adolescents and Adults (≥30 kg)
- Administer ORS ad libitum, up to approximately 2 L/day 1
- The 10 mL/kg principle still applies but with greater flexibility in total volume 4
Alternative Age-Based Approach
If precise weight is unavailable, use this simplified age-based algorithm:
Additional Considerations for Vomiting
- Replace 2 mL/kg of ORS for each vomiting episode 2, 3
- This is separate from and in addition to stool replacement 2
Critical Implementation Points
Continue replacement as long as diarrhea persists, even after initial rehydration is complete 1. The IDSA guidelines emphasize that ongoing loss replacement occurs during both the rehydration phase and the maintenance phase 1.
Use low-osmolarity ORS containing 50-90 mEq/L sodium for all replacements 1, 3. Appropriate commercial formulations include Pedialyte, CeraLyte, and Enfalac Lytren 1.
Do not use apple juice, Gatorade, or commercial soft drinks for replacement, as these contain inadequate sodium and excessive osmolality that worsens diarrhea 1, 2.
Monitoring for Inadequate Replacement
Reassess hydration status if the child develops:
- Increased thirst or sunken eyes 2
- High stool output (>10 mL/kg/hour) 2
- Signs of worsening dehydration despite ongoing replacement 2
If oral replacement fails or the child cannot tolerate adequate volumes, consider nasogastric administration at 15 mL/kg/hour or transition to intravenous therapy 3, 5.