What is the treatment for acute gastroenteritis?

Treatment of Acute Gastroenteritis

Oral rehydration solution (ORS) is the first-line treatment for mild to moderate dehydration in acute gastroenteritis, with intravenous fluids reserved only for severe dehydration or ORT failure. 1

Initial Assessment of Dehydration Status

Evaluate hydration through specific physical examination findings 1:

• Decreased skin turgor (abnormal skin turgor is one of the three most useful predictors of ≥5% dehydration) 2
• Abnormal capillary refill (another key predictor of significant dehydration) 2
• Abnormal respiratory pattern (third critical predictor) 2
• Dry mucous membranes, sunken eyes, altered mental status, tachycardia, decreased urine output 1

Categorize dehydration severity 1:

• Mild: <4% body weight lost (3-5%) 1, 3
• Moderate: 4-6% body weight lost (6-9%) 1, 3
• Severe: >6% body weight lost (≥10%) 1, 3

Rehydration Protocol

For Mild to Moderate Dehydration (First-Line)

Use low-osmolarity oral rehydration solution exclusively - avoid apple juice, Gatorade, or commercial soft drinks as these are inappropriate for rehydration 1, 3:

Dosing for initial rehydration 1:

• Infants and children: 50-100 mL/kg over 3-4 hours
• Adolescents and adults: 2-4 L of ORS over 3-4 hours

For patients refusing ORS: Consider nasogastric administration at 50-100 mL/kg over 3-4 hours 1, 3

Replace ongoing losses until symptoms resolve 1:

• Children <10 kg: 60-120 mL ORS per diarrheal stool/vomiting episode (up to ~500 mL/day)
• Children >10 kg: 120-240 mL ORS per diarrheal stool/vomiting episode (up to ~1 L/day)
• Adolescents/adults: Ad libitum intake up to ~2 L/day

For Severe Dehydration

Administer isotonic IV fluids (lactated Ringer's or normal saline) at 20 mL/kg over 30 minutes 1:

• Continue IV rehydration for 2-4 hours until pulse, perfusion, and mental status normalize 1, 3
• Transition to ORS once patient improves to replace remaining deficit 3

Nutritional Management

Continue breastfeeding throughout the diarrheal episode without interruption 1, 3

Resume age-appropriate diet during or immediately after rehydration - do not fast or withhold food for 24 hours as this does not improve outcomes 1, 3

Avoid foods high in simple sugars (soft drinks, undiluted apple juice) as they exacerbate diarrhea through osmotic effects 3

Pharmacological Adjuncts

Antiemetics

Ondansetron (0.15 mg/kg per dose) may be given to children >4 years and adolescents with significant vomiting to facilitate oral rehydration 1, 3:

• Reduces vomiting episodes and improves ORT compliance 4, 2
• Decreases need for IV hydration and hospitalization 4, 2
• Shortens ED length of stay 2

Antimotility Agents

Loperamide may be given to immunocompetent adults with acute watery diarrhea: 4 mg initially, then 2 mg after each loose stool 1, 3

Absolute contraindications for loperamide 1, 3, 5:

• Children <18 years (do not use) 3
• Inflammatory diarrhea (bloody diarrhea)
• Diarrhea with fever
• Suspected toxic megacolon
• Risk of paralytic ileus 5

Caution with loperamide 5:

• Avoid in patients taking CYP3A4 inhibitors (itraconazole), CYP2C8 inhibitors (gemfibrozil), or P-glycoprotein inhibitors (quinidine, ritonavir) due to increased cardiac risk 5
• Avoid in elderly patients taking QT-prolonging drugs (Class IA or III antiarrhythmics) 5
• Monitor for cardiac adverse reactions including QT prolongation, Torsades de Pointes, and arrhythmias 5

Antimicrobials

Antimicrobial agents have limited usefulness since viral agents cause approximately 70% of acute gastroenteritis episodes 3, 4:

• Consider only for: bloody diarrhea, recent antibiotic use, specific pathogen exposure, recent foreign travel, or immunodeficiency 3

Other Agents

Do not use adsorbents, antisecretory drugs, or toxin binders - they do not reduce diarrhea volume or duration 3

Infection Control Measures

Practice proper hand hygiene after toilet use, diaper changes, before/after food preparation, and after handling animals 1, 3

Use gloves and gowns when caring for patients with diarrhea 1, 3

Separate ill persons from well persons until at least 2 days after symptom resolution 3

Critical Pitfalls to Avoid

Do not delay rehydration while awaiting diagnostic testing - initiate rehydration promptly 3

Do not use inappropriate fluids (apple juice, sports drinks) as primary rehydration for moderate to severe dehydration 3

Do not give antimotility drugs to children or in bloody diarrhea cases 3

Do not unnecessarily restrict diet during or after rehydration 3

Disposition Criteria

Discharge when: tolerating oral intake, producing urine, clinically rehydrated 3

For acute diarrhea: If no clinical improvement in 48 hours, discontinue treatment and contact healthcare provider 5