What are the recommendations for managing diarrhea?

Management of Diarrhea

Oral rehydration solution (ORS) is the first-line therapy for all patients with diarrhea and mild to moderate dehydration—it is safer, less costly, and equally effective as intravenous fluids. 1, 2

Rehydration Strategy

Assessment of Hydration Status

Evaluate for signs of dehydration including:

• Thirst, orthostatic vital sign changes, decreased urination 3, 1
• Dry mucous membranes, decreased skin turgor, sunken eyes 3, 2
• Altered mental status, lethargy, hypovolemic shock 3

Oral Rehydration Solution (ORS)

Use reduced osmolarity ORS as the primary treatment for mild to moderate dehydration in all age groups. 1, 2

The WHO-recommended formulation contains approximately Na 90 mM, K 20 mM, Cl 80 mM, HCO₃ 30 mM, and glucose 111 mM. 3, 1 This can prevent 93% of diarrhea deaths. 4

Dosing by age:

• Children <2 years: 50-100 mL after each loose stool 3
• Children 2-12 years: 100-200 mL after each loose stool 3
• Adults: As much as desired, guided by thirst 3

For moderate dehydration where oral intake is difficult, consider nasogastric administration of ORS rather than proceeding directly to IV fluids. 1, 2

Intravenous Fluids

Reserve IV rehydration only for:

• Severe dehydration with shock 1, 2
• Altered mental status 1, 2
• Failure of ORS therapy 1, 2

Use isotonic fluids (lactated Ringer's or normal saline) until pulse, perfusion, and mental status normalize, then transition to ORS for remaining deficit replacement. 1, 2

Nutritional Management

Resume age-appropriate diet immediately during or after rehydration—never withhold food. 1, 2

• Continue breastfeeding throughout the diarrheal episode in all infants 3, 1, 2
• For formula-fed infants during acute phase, dilute formula with equal volume clean water until diarrhea stops 3
• For children >4-6 months, offer freshly prepared foods including cereal-bean or cereal-meat mixtures with vegetable oil every 3-4 hours 3
• After diarrhea resolves, provide one extra meal daily for one week 3

Early realimentation prevents malnutrition and may reduce stool output. 1

Zinc supplementation: In children 6 months to 5 years in zinc-deficient regions or with malnutrition, oral zinc reduces diarrhea duration. 1, 2

Antimicrobial Therapy

Do NOT give empiric antimicrobials for routine acute watery diarrhea without recent international travel. 1, 2

Specific Indications for Antimicrobials

Consider antimicrobial therapy ONLY when:

• Immunocompromised patients with severe illness 1, 2
• Ill-appearing infants <3 months with suspected bacterial etiology 2
• Bloody diarrhea with presumptive shigellosis 1, 2
• Recent international travelers with fever ≥38.5°C or signs of sepsis 1, 2
• Clinical features of sepsis with suspected enteric fever 1

Critical contraindication: Never use antimicrobials in STEC O157 or other Shiga toxin 2-producing E. coli infections—they increase risk of hemolytic uremic syndrome. 1, 2

Adjunctive Therapies

Antimotility Agents (Loperamide)

Never give loperamide to children <18 years with acute diarrhea. 1, 2, 5

For adults, loperamide may be used ONLY if:

• Patient is immunocompetent 1, 2
• Diarrhea is watery (not bloody) 1, 2
• No fever present 1, 2
• Patient is adequately hydrated first 1

Avoid loperamide in any patient with bloody diarrhea, fever, or suspected inflammatory diarrhea due to risk of toxic megacolon. 1, 2

Adult dosing: Initial 4 mg (two capsules), then 2 mg after each unformed stool, maximum 16 mg daily. 5

Antiemetics

Ondansetron may be given to children >4 years and adolescents to facilitate oral rehydration when vomiting is present. 1, 2

Probiotics

Probiotic preparations may be offered to reduce symptom severity and duration in immunocompetent patients, though evidence is moderate. 1, 2

Clinical Algorithm

1. Assess hydration status using clinical signs (thirst, orthostasis, mucous membranes, mental status) 3, 1, 2

2. For mild-moderate dehydration:

   • Administer ORS until clinical dehydration corrected 1, 2
   • Continue appropriate diet—do not withhold food 1, 2
   • Replace ongoing losses with ORS until symptoms resolve 1, 2

3. For severe dehydration:

   • Start IV isotonic fluids until stabilized 1, 2
   • Transition to ORS once patient can tolerate oral intake 1, 2
   • Resume feeding immediately 1, 2

4. Antimicrobials: Avoid unless specific high-risk features present 1, 2

5. Monitor: Weight and signs of dehydration throughout therapy to assess adequacy of rehydration 3

Critical Pitfalls to Avoid

• Never withhold food during diarrheal episodes—this worsens malnutrition and may prolong illness 1, 2
• Never give antimotility agents to children or patients with bloody/inflammatory diarrhea—risk of toxic megacolon 1, 2, 5
• Never use routine antimicrobials for acute watery diarrhea—they are ineffective and promote resistance 1, 2
• Never use antimicrobials in STEC infections—they increase hemolytic uremic syndrome risk 1, 2
• Never proceed directly to IV fluids when ORS can be tolerated—ORS is safer and equally effective 1, 2