What is the treatment for suspected gastroenteritis?

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

Initial Assessment and Rehydration Strategy

Evaluate Hydration Status

• Assess clinical signs including skin turgor, mental status, mucous membrane moisture, capillary refill, and vital signs to categorize dehydration severity 2
• Classify as mild (3-5%), moderate (6-9%), or severe (≥10%) based on clinical presentation 2
• The three most useful predictors of significant dehydration are abnormal capillary refill, abnormal skin turgor, and abnormal respiratory pattern 3

Mild to Moderate Dehydration

• Administer reduced osmolarity ORS as first-line therapy until clinical dehydration is corrected 1, 2
• Use commercially available low-osmolarity ORS (e.g., Pedialyte, CeraLyte); avoid sports drinks, apple juice, or soft drinks as they are inappropriate for rehydration 4
• Dosing: 50-100 mL/kg over 3-4 hours for children; 2-4 L for adults 4
• For patients who cannot tolerate oral intake, consider nasogastric administration of ORS 1

Severe Dehydration

• Administer isotonic intravenous fluids (lactated Ringer's or normal saline) for severe dehydration, shock, or altered mental status 1
• Continue IV rehydration until pulse, perfusion, and mental status normalize 1
• Transition to ORS to replace remaining deficit once the patient improves 1, 2

Ongoing Management

Replace Ongoing Losses

• Continue ORS to replace ongoing losses until diarrhea and vomiting resolve 1, 2
• Administer 10 mL/kg ORS for each watery stool and 2 mL/kg for each vomiting episode 2

Nutritional Management

• Continue breastfeeding throughout the diarrheal episode in infants 1, 2, 4
• Resume age-appropriate diet during or immediately after rehydration is completed 1, 4
• Avoid fasting or restrictive diets as early refeeding is recommended 2, 4
• Avoid foods high in simple sugars (soft drinks, undiluted apple juice) as they can worsen diarrhea through osmotic effects 2

Pharmacological Adjuncts

Antiemetics

• Ondansetron may be given to children >4 years and adolescents with significant vomiting to facilitate oral rehydration 1, 4
• Dose: 0.15 mg/kg per dose 4
• This can decrease vomiting, improve oral intake success, and reduce need for IV hydration 3

Antimotility Agents

• Loperamide is contraindicated in children <18 years with acute diarrhea 1, 5
• Loperamide may be given to immunocompetent adults with acute watery diarrhea once adequately hydrated 1, 4
• Avoid loperamide in inflammatory diarrhea, bloody diarrhea, fever, or suspected toxic megacolon at any age 1
• The FDA warns of cardiac adverse reactions including QT prolongation and Torsades de Pointes with higher than recommended doses 5

Probiotics and Zinc

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

Antimicrobial Therapy

When NOT to Use Antibiotics

• Empiric antimicrobial therapy is NOT recommended for most immunocompetent patients with acute watery diarrhea 1, 6
• Viral agents are the predominant cause, making antibiotics unnecessary in most cases 2

When to Consider Antibiotics

• Infants <3 months with suspected bacterial etiology 1
• Ill patients with fever, abdominal pain, bloody diarrhea, and bacillary dysentery (presumptive Shigella) 1
• Recent international travel with fever ≥38.5°C or signs of sepsis 1
• Immunocompromised patients with severe illness and bloody diarrhea 1
• Avoid antimicrobials in STEC O157 and other Shiga toxin 2-producing strains due to risk of hemolytic uremic syndrome 1, 6

Empiric Antibiotic Choice (when indicated)

• Adults: fluoroquinolone (ciprofloxacin) or azithromycin based on local susceptibility and travel history 1
• Children: third-generation cephalosporin for infants <3 months or azithromycin based on local patterns 1

Critical Pitfalls to Avoid

• Do not delay rehydration while awaiting diagnostic testing—initiate ORS promptly 2
• Do not use inappropriate fluids (sports drinks, apple juice) as primary rehydration for moderate to severe dehydration 2
• Do not give antimotility drugs to children or in cases of bloody diarrhea 1, 5
• Do not unnecessarily restrict diet during or after rehydration 1, 2
• Do not start broad-spectrum antibiotics empirically when rehydration alone is indicated 6

Infection Control

• Practice hand hygiene after toilet use, diaper changes, before/after food preparation, and after handling animals 1, 4
• Use gloves and gowns when caring for patients with diarrhea 1, 2
• Clean and disinfect contaminated surfaces promptly 2