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, shock, altered mental status, or failure of oral rehydration. 1, 2

Initial Assessment

Assess dehydration severity through specific clinical signs rather than laboratory tests 1, 2:

• Skin turgor 1, 2
• Mental status 1, 2
• Mucous membrane moisture 1, 2
• Capillary refill time 1, 2
• Urine output 1, 2

Categorize dehydration as 1, 2:

• Mild: 3-5% body weight loss 1, 2
• Moderate: 6-9% body weight loss 1, 2
• Severe: ≥10% body weight loss 1, 2

Rehydration Strategy

Mild to Moderate Dehydration (First-Line Treatment)

Begin ORS immediately using small, frequent volumes 1:

• Start with 5-10 mL every 1-2 minutes using a spoon or syringe 1
• Gradually increase volume as tolerated without triggering vomiting 1
• Target: 50-100 mL/kg over 3-4 hours for children 2
• Target: 2-4 L over 3-4 hours for adolescents and adults 2

Use low-osmolarity ORS formulations, not sports drinks or juices 1. This approach successfully rehydrates >90% of children with vomiting and diarrhea without antiemetic medication 1.

Replace ongoing losses 1:

• 10 mL/kg ORS for each watery stool 1
• 2 mL/kg ORS for each vomiting episode 1

If oral intake is refused or inadequate, consider nasogastric administration of ORS 1.

Severe Dehydration (Requires IV Therapy)

Administer isotonic intravenous fluids (lactated Ringer's or normal saline) at 20 mL/kg over 30 minutes 2. Continue IV rehydration until pulse, perfusion, and mental status normalize 1, 2. Once the patient improves, transition to ORS to replace remaining deficit 1.

Other indications for IV therapy include shock, altered mental status, failure of oral rehydration, or ileus 1.

Pharmacological Management

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, 2. This can decrease the need for intravenous fluids and hospitalization 3.

Antimotility Agents

Loperamide is contraindicated in all children <18 years with acute diarrhea 1, 2. For immunocompetent adults with acute watery diarrhea who are adequately hydrated, loperamide may be given (4 mg initially, then 2 mg after each loose stool) 1, 2.

Antimicrobials

Antimicrobial therapy has limited usefulness since viral agents cause most cases 1. Consider empiric antimicrobials only for 2:

• Infants <3 months with suspected bacterial etiology: third-generation cephalosporin 2
• Fever, abdominal pain, bloody diarrhea, and bacillary dysentery: fluoroquinolone (ciprofloxacin) or azithromycin 2

Adjunctive Therapies

Probiotics may reduce symptom severity and duration in both adults and children 1, 2.

Zinc supplementation (10-20 mg daily) reduces diarrhea duration in children 6 months to 5 years in areas with high zinc deficiency prevalence or in malnourished children 1, 2.

Nutritional Management

Continue breastfeeding throughout the diarrheal episode 1. Resume age-appropriate diet during or immediately after rehydration—early refeeding is recommended rather than fasting or restrictive diets 1. Avoid foods high in simple sugars (soft drinks, undiluted apple juice) as they can exacerbate diarrhea through osmotic effects 1.

Monitoring and Reassessment

Reassess hydration status after 2-4 hours 1. If still dehydrated, reestimate deficit and restart rehydration 1. Monitor vital signs every 2-4 hours, including capillary refill, skin turgor, mental status, and mucous membrane moisture 1.

Infection Control

Practice proper hand hygiene after using the toilet, changing diapers, before and after food preparation, and before eating 1, 2. Use gloves and gowns when caring for people with diarrhea 1, 2. Clean and disinfect contaminated surfaces promptly 1. Separate ill persons from well persons until at least 2 days after symptom resolution 1.

Critical Pitfalls to Avoid

Do not delay rehydration therapy while awaiting diagnostic testing—initiate rehydration 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.

Do not unnecessarily restrict diet during or after rehydration 1.

Do not rely on antidiarrheal agents like metamizole, as this shifts focus away from appropriate fluid, electrolyte, and nutritional therapy 1.