What is the first line of treatment for diarrhea?

First-Line Treatment for Diarrhea

Reduced osmolarity oral rehydration solution (ORS) is the first-line therapy for mild to moderate dehydration in infants, children, and adults with acute diarrhea from any cause. 1

Assessment of Dehydration

Before initiating treatment, assess the degree of dehydration:

• Mild dehydration (3-5% fluid deficit): Slightly dry mucous membranes, increased thirst, normal or slightly increased heart rate 1
• Moderate dehydration (6-9% fluid deficit): Dry mucous membranes, sunken eyes, decreased skin turgor, decreased urine output 1
• Severe dehydration (≥10% fluid deficit): Shock or near shock, altered mental status, very dry mucous membranes, significantly decreased skin turgor 1

Treatment Algorithm Based on Dehydration Severity

For Mild to Moderate Dehydration

1. Oral Rehydration Solution (ORS)

   • For mild dehydration: Administer 50 mL/kg ORS over 2-4 hours 1
   • For moderate dehydration: Administer 100 mL/kg ORS over 2-4 hours 1
   • Start with small volumes (e.g., one teaspoon) and gradually increase as tolerated 1
   • Reassess hydration status after 2-4 hours 1

2. Replace Ongoing Losses

   • Replace each watery stool with approximately 10 mL/kg of ORS 1
   • Replace each episode of vomiting with 2 mL/kg of ORS 1

For Severe Dehydration

1. Intravenous Rehydration (Medical Emergency)
   • Administer boluses (20 mL/kg) of isotonic fluids (Ringer's lactate or normal saline) until pulse, perfusion, and mental status normalize 1
   • Once the patient's level of consciousness returns to normal, transition to oral rehydration 1
   • Continue IV rehydration until pulse, perfusion, and mental status normalize and there is no risk of aspiration 1

Dietary Management

1. For Infants

   • Continue breastfeeding throughout the diarrheal episode 1
   • For bottle-fed infants, resume full-strength formula immediately after rehydration 1

2. For Children and Adults

   • Resume age-appropriate diet during or immediately after rehydration 1
   • Early resumption of feeding speeds recovery 1

Adjunctive Treatments

1. Antimotility Agents

   • Should NOT be given to children <18 years with acute diarrhea 1
   • May be given to immunocompetent adults with acute watery diarrhea (e.g., loperamide) 1
   • Avoid in cases of bloody diarrhea, fever, or suspected inflammatory diarrhea 1

2. Antimicrobial Therapy

   • In most people with acute watery diarrhea without recent international travel, empiric antimicrobial therapy is NOT recommended 1
   • Exceptions include immunocompromised patients or ill-appearing young infants 1

Important Considerations and Pitfalls

• Commercial sports drinks, sodas, and juices are NOT appropriate substitutes for ORS as they have inappropriate sodium and glucose concentrations 1, 2
• Nasogastric administration of ORS may be considered in those who cannot tolerate oral intake 1
• An ORS tolerance test can help determine if a patient can be managed at home - patients who can tolerate approximately 25 mL/kg of ORS in a supervised setting are more likely to succeed with home management 3
• Antimicrobial therapy should be avoided in cases of suspected STEC (Shiga toxin-producing E. coli) infections 1
• Laboratory studies are rarely needed in uncomplicated cases; stool cultures are indicated only for bloody diarrhea 1

ORS Composition

• Reduced osmolarity ORS (WHO recommendation) contains sodium 75-90 mEq/L with glucose under 2.5% 1, 2
• Commercial ORS formulations include Pedialyte, CeraLyte, and Enfalac Lytren 1
• For maintenance after rehydration, solutions with sodium 40-60 mEq/L can be used 4, 5