What is the treatment for gastroenteritis?

Treatment of Gastroenteritis

Oral rehydration solution (ORS) is the first-line treatment for mild to moderate dehydration in gastroenteritis, with intravenous fluids reserved only for severe dehydration or ORS failure. 1, 2

Initial Assessment

Evaluate hydration status through specific clinical signs rather than relying on laboratory tests alone:

• Assess skin turgor, mental status, mucous membrane moisture, capillary refill time, and urine output to determine dehydration severity 1, 3
• Categorize dehydration as mild (3-5% body weight loss), moderate (6-9% body weight loss), or severe (≥10% body weight loss) based on these clinical findings 1, 2

Rehydration Strategy by Severity

Mild to Moderate Dehydration

Use commercially available low-osmolarity ORS (such as Pedialyte or CeraLyte) as primary therapy—sports drinks, apple juice, and soft drinks are inappropriate for rehydration: 3

• Administer 50-100 mL/kg of ORS over 3-4 hours for infants and children 1, 3
• Administer 2-4 L of ORS over 3-4 hours for adolescents and adults 1, 3
• Consider nasogastric administration of ORS for patients who cannot tolerate oral intake or refuse to drink adequately 4, 2

Severe Dehydration

Administer isotonic intravenous fluids (lactated Ringer's or normal saline) at 20 mL/kg over 30 minutes: 1, 3

• Continue IV rehydration until pulse, perfusion, and mental status normalize 3
• Transition to ORS to replace remaining deficit once the patient improves 2, 3

Ongoing Losses

Replace ongoing losses with ORS until diarrhea and vomiting resolve: 3

• For children <10 kg: 60-120 mL ORS for each diarrheal stool or vomiting episode (up to ~500 mL/day) 3
• For children >10 kg: 120-240 mL ORS for each diarrheal stool or vomiting episode (up to ~1 L/day) 3
• For adolescents and adults: ad libitum intake up to ~2 L/day 3

Nutritional Management

Resume age-appropriate diet during or immediately after rehydration—fasting or restrictive diets do not improve outcomes and should be avoided: 1, 2, 3

• Continue breastfeeding throughout the diarrheal episode in infants 1, 2, 3
• Early refeeding is recommended rather than withholding food for 24 hours 3
• Avoid foods high in simple sugars (soft drinks, undiluted apple juice) as they can exacerbate diarrhea through osmotic effects 2

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, 3

• This reduces the need for intravenous fluids and hospitalization 5

Antimotility Agents

Loperamide is contraindicated in children <18 years with acute diarrhea: 1, 2

• Loperamide may be given to immunocompetent adults with acute watery diarrhea once adequately hydrated (4 mg initially, then 2 mg after each loose stool) 2, 3
• Avoid antimotility agents in inflammatory diarrhea, diarrhea with fever, bloody diarrhea, or suspected toxic megacolon 3

Antimicrobial Therapy

Empiric antimicrobial therapy for bloody diarrhea is not recommended in immunocompetent patients except in specific circumstances: 4

• Infants <3 months with suspected bacterial etiology should receive a third-generation cephalosporin 4
• Ill immunocompetent patients with fever, abdominal pain, bloody diarrhea, and bacillary dysentery should receive empiric therapy with either a fluoroquinolone (ciprofloxacin) or azithromycin, depending on local susceptibility patterns and travel history 4
• Antimicrobial therapy for STEC O157 and other STEC producing Shiga toxin 2 should be avoided 4
• Viral gastroenteritis (the predominant cause) does not benefit from antimicrobial therapy 2

Adjunctive Therapies

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

• Probiotics may reduce symptom severity and duration in both adults and children 2

Infection Control Measures

Practice proper hand hygiene after using the toilet, changing diapers, before and after food preparation, and before eating: 1, 2, 3

• Use gloves and gowns when caring for people with diarrhea 1, 2, 3
• Clean and disinfect contaminated surfaces promptly 1, 2
• Separate ill persons from well persons until at least 2 days after symptom resolution 1, 2

Common Pitfalls to Avoid

Do not delay rehydration therapy while awaiting diagnostic testing—rehydration should be initiated promptly: 2

Do not use inappropriate fluids like apple juice or sports drinks as primary rehydration solutions for moderate to severe dehydration: 2, 3

Do not administer antimotility drugs to children or in cases of bloody diarrhea: 2

Do not unnecessarily restrict diet during or after rehydration: 2

Do not use adsorbents, antisecretory drugs, or toxin binders as they do not demonstrate effectiveness in reducing diarrhea volume or duration: 2