What is the treatment for watery diarrhea?

Treatment of Watery Diarrhea

For most patients with acute watery diarrhea without recent international travel, oral rehydration therapy (ORS) is the cornerstone of treatment, and empiric antimicrobial therapy is not recommended. 1, 2

Initial Assessment and Rehydration Strategy

Assess dehydration severity immediately by examining mental status, skin turgor, mucous membranes, pulse, perfusion, and capillary refill time. 2, 3

Mild Dehydration (3-5% fluid deficit)

• Administer 50 mL/kg of reduced osmolarity ORS over 2-4 hours. 2
• ORS should contain 50-90 mEq/L of sodium for optimal absorption. 1, 4

Moderate Dehydration (6-9% fluid deficit)

• Administer 100 mL/kg of ORS over 2-4 hours. 2
• Replace ongoing losses with 10 mL/kg of ORS for each watery stool and 2 mL/kg for each vomiting episode. 2, 3

Severe Dehydration (≥10% fluid deficit, shock, or altered mental status)

• Immediate intravenous rehydration is mandatory with isotonic fluids (lactated Ringer's or normal saline). 1, 2
• Administer 20 mL/kg boluses (or 60-100 mL/kg total) over the first 2-4 hours until pulse, perfusion, and mental status normalize. 3, 4
• Transition to oral rehydration once circulation is restored to complete fluid replacement. 2, 3

Special Considerations for Vomiting

• For children with vomiting, administer small volumes (5-10 mL) of ORS every 1-2 minutes using a spoon, syringe, or medicine dropper, gradually increasing as tolerated. 2, 3
• Common pitfall: Allowing a thirsty child to drink large volumes of ORS ad libitum worsens vomiting. 2
• Ondansetron may be given to children >4 years of age only after adequate hydration is achieved to facilitate oral rehydration. 2, 5

Nutritional Management

• Continue breastfeeding throughout the entire diarrheal episode without interruption. 2, 3
• Resume full-strength formula immediately upon rehydration for bottle-fed infants. 2, 5
• Resume age-appropriate diet during or immediately after rehydration is completed, including starches, cereals, yogurt, fruits, and vegetables. 2, 3
• Avoid foods high in simple sugars and fats. 2

When Antimicrobial Therapy Is NOT Indicated

Empiric antimicrobial therapy is explicitly not recommended for acute watery diarrhea in most patients without recent international travel. 1, 5 This includes:

• Uncomplicated watery diarrhea in immunocompetent adults and children. 1
• Persistent watery diarrhea lasting ≥14 days. 1
• Asymptomatic contacts of patients with watery diarrhea. 1

Exceptions Where Antimicrobial Therapy May Be Considered

• Immunocompromised patients with severe illness. 1
• Young infants who appear ill. 5
• Patients with clinical features of sepsis (body temperature ≥38.5°C, signs of sepsis). 1
• Patients with recent international travel who have fever or signs of sepsis—treat with ciprofloxacin or azithromycin depending on local susceptibility patterns. 1

Adjunctive Therapies

Zinc Supplementation

• Recommended for children 6 months to 5 years of age who reside in countries with high zinc deficiency prevalence or show signs of malnutrition. 2, 3
• Reduces diarrhea duration. 2

Probiotics

• May be offered to reduce symptom severity and duration in immunocompetent children with infectious diarrhea. 2

Critical Contraindications

Antimotility drugs (loperamide) are absolutely contraindicated in all children <18 years of age due to risks of respiratory depression, serious cardiac adverse reactions including cardiac arrest, syncope, Torsades de Pointes, and death. 2, 5, 6

• Loperamide should also be avoided in adults with:
  • Inflammatory diarrhea, bloody diarrhea, or fever. 2
  • Risk of toxic megacolon. 2
  • Patients taking QT-prolonging drugs (Class IA or III antiarrhythmics, antipsychotics, certain antibiotics). 6

Warning Signs Requiring Immediate Medical Attention

• Bloody diarrhea (dysentery). 2
• Severe dehydration with shock or near-shock. 2
• Intractable vomiting preventing successful oral rehydration. 2
• High stool output (>10 mL/kg/hour). 2
• Decreased urine output, lethargy, or irritability. 2
• Signs of glucose malabsorption (increased stool output with ORS administration). 2

Key Clinical Pitfalls to Avoid

• Do not delay rehydration while awaiting diagnostic test results. 5
• Do not restrict diet during or after rehydration—early feeding improves outcomes. 5
• Do not prescribe empiric antibiotics for uncomplicated watery diarrhea—this promotes resistance without benefit. 5
• Do not use antimotility agents in any pediatric patient or in adults with inflammatory diarrhea. 2, 5, 6