What are the latest guidelines for managing acute gastroenteritis?

Latest Guidelines for Acute Gastroenteritis Management

Rehydration: The Cornerstone of Treatment

Oral rehydration solution (ORS) is the first-line treatment for mild to moderate dehydration and should be initiated immediately without waiting for diagnostic testing. 1

Assessment of Dehydration Severity

• Evaluate hydration status through skin turgor, mental status, mucous membrane moisture, capillary refill, and vital signs 1
• Categorize dehydration as:
  • Mild (3-5%): Minimal clinical signs 1
  • Moderate (6-9%): Decreased skin turgor, dry mucous membranes, reduced urine output 1
  • Severe (≥10%): Signs of shock, altered mental status, poor perfusion 1

Oral Rehydration Protocol

• Use low-osmolarity ORS formulations rather than sports drinks or juices 1
• For moderate dehydration: administer 100 mL/kg over 2-4 hours 1
• Replace ongoing losses: 10 mL/kg for each watery stool and 2 mL/kg for each vomiting episode 1
• Start with small volumes using a syringe or medicine dropper if vomiting persists, gradually increasing as tolerated 1
• Nasogastric administration may be considered for patients who cannot tolerate oral intake or refuse to drink adequately 1

Intravenous Rehydration

Reserve IV fluids only for severe dehydration, shock, altered mental status, failure of oral rehydration therapy, or ileus. 1

• Use isotonic fluids such as lactated Ringer's or normal saline 1
• Continue IV rehydration until pulse, perfusion, and mental status normalize 1
• Transition to ORS to replace remaining deficit once patient improves 1

Nutritional Management

Resume age-appropriate diet during or immediately after rehydration—early refeeding is recommended rather than fasting or restrictive diets. 1

• Continue breastfeeding in infants throughout the diarrheal episode 1
• Avoid foods high in simple sugars (soft drinks, undiluted apple juice) as they exacerbate diarrhea through osmotic effects 1

Pharmacological Management

Antiemetics

Ondansetron may be given to children >4 years and adolescents to facilitate oral rehydration when vomiting is significant. 1

• Ondansetron works as a selective 5-HT3 receptor antagonist, blocking serotonin at the chemoreceptor trigger zone without antimotility effects 2
• Critical contraindication: Avoid ondansetron in inflammatory diarrhea (suspected or proven) or diarrhea with fever due to risk of toxic megacolon 2
• Avoid in children with cardiac disease due to QT interval prolongation risk 2
• Ondansetron facilitates rehydration but may increase stool volume—it treats vomiting, not diarrhea itself 2

Antimotility Agents

Loperamide should NOT be given to children <18 years with acute diarrhea. 1, 3

• In immunocompetent adults with acute watery diarrhea, loperamide may be given only after adequate hydration 1
• Never use in bloody diarrhea or children due to risk of serious complications including toxic megacolon 1, 3
• Loperamide can cause cardiac adverse reactions including QT prolongation, especially with CYP3A4 or CYP2C8 inhibitors 3

Probiotics and Zinc

• Probiotics may reduce symptom severity and duration in both adults and children 1
• Zinc supplementation reduces diarrhea duration in children 6 months to 5 years in areas with high zinc deficiency or malnutrition 1

Antimicrobials

Antimicrobial agents have limited usefulness since viral agents cause approximately 70% of acute gastroenteritis. 1, 4

• Consider antimicrobials only for: bloody diarrhea, recent antibiotic use (test for C. difficile), exposure to specific pathogens, recent foreign travel, or immunodeficiency 1
• Oral vancomycin is indicated specifically for C. difficile-associated diarrhea and S. aureus enterocolitis 5

Agents to Avoid

Do NOT use adsorbents, antisecretory drugs, or toxin binders—they do not reduce diarrhea volume or duration and shift focus away from appropriate fluid and nutritional therapy. 1

Infection Control Measures

• Practice hand hygiene after toilet use, diaper changes, before food preparation and eating, and after handling soiled items 1
• Use gloves and gowns when caring for people with diarrhea 1
• Clean and disinfect contaminated surfaces promptly 1
• Separate ill persons from well persons until at least 2 days after symptom resolution 1

Monitoring and Reassessment

• Monitor vital signs every 2-4 hours including capillary refill, skin turgor, mental status, and mucous membrane moisture 1
• Reassess hydration status after 2-4 hours; if still dehydrated, reestimate deficit and restart rehydration 1
• Daily weights to track rehydration progress 1

Disposition Criteria

Plan discharge when patient is tolerating oral intake, producing urine, clinically rehydrated, and afebrile for 24 hours (if bacterial infection confirmed). 1

Critical Pitfalls to Avoid

• Never delay rehydration while awaiting diagnostic testing—initiate ORS immediately 1
• Do not use apple juice or sports drinks as primary rehydration solutions for moderate to severe dehydration 1
• Never give antimotility drugs to children or in bloody diarrhea cases 1
• Do not unnecessarily restrict diet during or after rehydration 1
• Do not neglect infection control measures as this leads to outbreaks 1