What are the current guidelines for treating acute gastroenteritis?

Current Guidelines for Treating Acute Gastroenteritis

Oral rehydration solution (ORS) is the first-line treatment for mild to moderate dehydration in both children and adults with acute gastroenteritis, with early resumption of normal diet immediately after rehydration. 1, 2

Initial Assessment and Hydration Status

Evaluate dehydration severity through specific clinical signs including skin turgor, mental status, mucous membrane moisture, capillary refill, and vital signs 1:

• Mild dehydration (3-5% fluid deficit): Minimal clinical signs
• Moderate dehydration (6-9% fluid deficit): Decreased skin turgor, dry mucous membranes, reduced urine output
• Severe dehydration (≥10% fluid deficit): Signs of shock, altered mental status, poor perfusion 1

Rehydration Strategy

Oral Rehydration Therapy (First-Line)

For mild to moderate dehydration, use low-osmolarity ORS as primary treatment 1, 2:

• Children: Administer 50-100 mL/kg over 3-4 hours 2
• Moderate dehydration: Start with 100 mL/kg over 2-4 hours 1
• If vomiting is present: Give small volumes (5-10 mL) every 1-2 minutes using a syringe or medicine dropper, gradually increasing as tolerated 1, 2
• Replace ongoing losses: 10 mL/kg ORS for each watery stool and 2 mL/kg for each vomiting episode 1

Nasogastric administration of ORS should be considered for patients who cannot tolerate oral intake or refuse to drink adequately, but have normal mental status 1, 2. This is just as effective as intravenous rehydration and is preferred over IV therapy in these cases 3.

Intravenous Rehydration (Reserved for Specific Situations)

Reserve IV rehydration for 1:

• Severe dehydration with signs of shock
• Altered mental status
• Failure of oral rehydration therapy
• Ileus

Use isotonic fluids (lactated Ringer's or normal saline) until pulse, perfusion, and mental status normalize, then transition to ORS 1.

Nutritional Management

Resume age-appropriate diet during or immediately after rehydration—do not withhold food 1, 2:

• Continue breastfeeding throughout the diarrheal episode in infants 1, 2
• Early refeeding is recommended rather than fasting or restrictive diets 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, 2. This improves tolerance of ORS and reduces hospitalization rates 4.

Antimotility Agents

Loperamide should NOT be given to children <18 years with acute diarrhea 1, 2:

• May be given to immunocompetent adults with acute watery diarrhea once adequately hydrated 1, 2
• Avoid in inflammatory diarrhea, bloody diarrhea, fever, or suspected toxic megacolon 2
• In neutropenic patients with C. difficile infection, high-dose loperamide may predispose to toxic dilatation—repeated assessment is necessary 5

Probiotics and Zinc

• Probiotics may reduce symptom severity and duration in both adults and children 1, 2
• Zinc supplementation reduces diarrhea duration in children 6 months to 5 years in areas with high zinc deficiency or malnutrition 1

Antimicrobial Therapy

Antimicrobial agents have limited usefulness since viral agents are the predominant cause 1. Consider antimicrobial therapy only for 1, 6:

• Bloody diarrhea
• Recent antibiotic use (test for C. difficile)
• Recent foreign travel
• Immunodeficiency
• Severe symptoms with confirmed bacterial infection

Infection Control Measures

Implement strict infection control to prevent transmission 1:

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

Monitoring and Reassessment

Reassess hydration status after 2-4 hours of ORS therapy 1:

• If still dehydrated, reestimate deficit and restart rehydration
• Monitor vital signs every 2-4 hours
• Track daily weights to assess rehydration progress

Critical Pitfalls to Avoid

• Do not delay rehydration while awaiting diagnostic testing—initiate treatment promptly 1
• Do not use sports drinks or apple juice as primary rehydration solutions for moderate to severe dehydration 1
• Do not administer antimotility drugs to children or in cases of bloody diarrhea 1, 2
• Do not unnecessarily restrict diet during or after rehydration 1
• Do not routinely use antimotility agents, adsorbents, antisecretory drugs, or toxin binders—they do not reduce diarrhea volume or duration 1

When to Seek Medical Attention

Immediate evaluation is warranted for 2:

• Inability to tolerate oral fluids
• Worsening signs of dehydration
• Development of bloody diarrhea
• Significant increase in fever
• Signs of severe dehydration or shock