How should acute gastroenteritis be managed in adults and children?

Management of Acute Gastroenteritis in Adults and Children

The cornerstone of acute gastroenteritis management is oral rehydration therapy with hypoosmolar solutions, initiated immediately upon presentation, with early refeeding and no dietary restrictions—antimotility agents should never be used in children under 18 years of age. 1

Rehydration: The Primary Treatment

Fluid and electrolyte replacement is the foundation of management and takes priority over all other interventions. 1

Oral Rehydration Therapy (ORT)

• Use hypoosmolar oral rehydration solutions as first-line treatment for mild-to-moderate dehydration in both children and adults 2
• ORT is superior to intravenous rehydration when tolerated 2
• Continue breastfeeding without interruption in infants 2
• For severe dehydration or inability to tolerate oral fluids, use enteral (nasogastric) or intravenous rehydration 2

Feeding Recommendations

• Resume normal feeding immediately—do not withhold solid foods for 24 hours 1
• Continue regular diet with no dietary modifications in most cases 1
• In hospitalized non-breastfed infants and young children, consider lactose-free feeds (reduces diarrhea duration by 18 hours and treatment failure by 50%) 1
• The BRAT diet has limited supporting evidence and is not necessary 1

Antiemetic Therapy

Ondansetron can be given to children >4 years of age and adolescents with vomiting to facilitate oral rehydration tolerance. 1

• Reduces immediate need for hospitalization and IV rehydration 1
• May increase stool volume as a side effect 1
• Not recommended for routine use in children <4 years of age 1
• Effective in reducing vomiting but does not decrease 72-hour hospitalization rates 1

Critical Caveat

Be aware of FDA warnings regarding potential cardiac effects with ondansetron 2

Antimotility Agents: Age-Specific Restrictions

Children

Loperamide should NEVER be given to children <18 years of age with acute diarrhea (strong recommendation). 1

• Deaths reported in 0.54% of children receiving loperamide, all in children <3 years old 1
• Adverse events include ileus, abdominal distension, and lethargy 1

Adults

Loperamide may be given to immunocompetent adults with acute watery diarrhea only. 1

Absolute contraindications at any age:

• Inflammatory diarrhea (bloody stools)
• Fever with diarrhea
• Suspected or proven cases where toxic megacolon may develop 1

When Ancillary Medications Can Be Considered

Antimotility, antinausea, or antiemetic agents can be considered only after adequate hydration is achieved, but these are never substitutes for fluid and electrolyte therapy 1

Diagnostic Testing

• Not routinely needed for mild symptoms resolving within one week 3
• Reserve stool testing for:
  • Severe symptoms or bloody diarrhea
  • Prolonged symptoms (>7 days)
  • Suspected outbreaks
  • Recent antibiotic exposure (test for Clostridioides difficile)
  • Immunocompromised patients 2, 3

Antimicrobial Therapy

Generally not recommended except for specific situations 4, 3:

• C. difficile infection
• Specific bacterial pathogens (Shigella, Vibrio cholerae)
• Severe cases in immunocompromised hosts
• Travel-related diarrhea with severe symptoms

Additional Supportive Measures

Evidence supports the use of:

• Specific probiotics (Lactobacillus GG or Saccharomyces boulardii) 2
• Diosmectite or racecadotril (not available in North America) 1, 2
• Bismuth subsalicylate (mildly effective) 1

Common Pitfalls to Avoid

1. Never use loperamide in children regardless of symptom severity—the mortality risk outweighs any benefit
2. Do not withhold feeding—early refeeding decreases intestinal permeability and reduces illness duration 1
3. Do not routinely use antibiotics—most cases are viral and self-limited 4
4. Avoid antimotility agents with fever or bloody diarrhea at any age due to toxic megacolon risk 1
5. Most cases can be managed outpatient; hospitalization is reserved for those requiring enteral/parenteral rehydration 2