What is the recommended treatment approach for a patient with acute diarrhea?

Acute Diarrhea Treatment Approach

The cornerstone of acute diarrhea management is oral rehydration therapy (ORT) using reduced-osmolarity oral rehydration solution (ORS), with treatment intensity determined by clinical assessment of dehydration severity; antimotility agents like loperamide are absolutely contraindicated in children under 18 years of age and should be avoided in adults with bloody diarrhea, fever, or inflammatory symptoms. 1, 2

Initial Assessment: Classify Dehydration Severity

Rapidly assess hydration status by examining:

• Capillary refill time (most reliable predictor) 1
• Skin turgor (pinch test for tenting) 1, 3
• Mucous membrane moisture 1, 3
• Mental status and pulse 1, 3
• Weight loss (most reliable clinical indicator in children) 3

Classify dehydration into three categories:

• Mild (3-5% fluid deficit): Increased thirst, slightly dry mucous membranes 1, 4
• Moderate (6-9% fluid deficit): Loss of skin turgor, dry mucous membranes, skin tenting 1, 4
• Severe (≥10% fluid deficit): Severe lethargy/altered consciousness, prolonged skin tenting (>2 seconds), cool/poorly perfused extremities, decreased capillary refill, rapid deep breathing (acidosis), signs of shock 1, 4

Rehydration Protocol by Severity

Severe Dehydration (≥10% deficit)

This is a medical emergency requiring immediate IV rehydration: 1, 3

• Administer 20 mL/kg boluses of Ringer's lactate or normal saline IV immediately 1, 3
• Repeat boluses until pulse, perfusion, and mental status normalize 1, 3
• Monitor continuously for improvement in vital signs and perfusion 1
• Once circulation is restored, transition to ORS for the remaining fluid deficit 1, 4

Moderate Dehydration (6-9% deficit)

• Administer 100 mL/kg of ORS over 2-4 hours 1, 3, 4
• Use small, frequent volumes initially (5-10 mL every 1-2 minutes) if vomiting is present 3, 4
• Consider nasogastric administration if oral intake is not tolerated 1

Mild Dehydration (3-5% deficit)

• Administer 50 mL/kg of ORS over 2-4 hours 1, 3, 4
• Use the same small-volume, frequent administration technique 3

Critical technique for vomiting patients: Give 5 mL of ORS every 1-2 minutes using a spoon or syringe, gradually increasing volume as tolerated—this prevents triggering more vomiting while simultaneously correcting dehydration 3, 4

Replace Ongoing Losses

After initial rehydration:

• 10 mL/kg of ORS for each watery/loose stool 1, 3, 4
• 2 mL/kg of ORS for each vomiting episode 1, 3, 4
• Continue until diarrhea and vomiting resolve 3, 4

Nutritional Management

Resume feeding immediately upon rehydration—there is no justification for "bowel rest": 1

• Continue breastfeeding on demand throughout the entire episode without interruption 1, 3, 4
• Resume full-strength formula immediately for bottle-fed infants (lactose-free or lactose-reduced preferred) 3, 4
• Resume age-appropriate diet during or immediately after rehydration 1, 4
• Recommended foods: starches, cereals, yogurt, fruits, vegetables 1, 4
• Avoid: foods high in simple sugars and fats 1, 4

Pharmacologic Considerations

Antimotility Agents: CONTRAINDICATED in Most Cases

Loperamide is absolutely contraindicated in: 1, 2

• All children <18 years of age (risk of respiratory depression and serious cardiac adverse reactions including Torsades de Pointes) 1, 2
• Adults with bloody diarrhea, fever, or inflammatory symptoms (risk of toxic megacolon) 2, 5
• Patients taking QT-prolonging drugs (Class IA/III antiarrhythmics, antipsychotics, certain antibiotics) 2
• Patients with cardiac risk factors or electrolyte abnormalities 2

In adults with uncomplicated watery diarrhea only: Loperamide may be used at recommended doses (initial 4 mg, then 2 mg after each unformed stool, maximum 16 mg/day) 2, 5, 6

Antiemetics

• Ondansetron may be considered in children >4 years of age if vomiting prevents adequate oral intake (reduces vomiting rate, improves ORS tolerance, reduces need for IV rehydration) 1, 4
• Contraindicated in infants <4 years of age 3

Antibiotics: Rarely Indicated

Consider antibiotics ONLY when: 1, 3, 4

• Bloody diarrhea (dysentery) with fever is present 3, 4, 5
• Watery diarrhea persists >5 days 1, 3
• Stool cultures indicate a specific treatable pathogen 1, 4
• Patient is immunocompromised 5, 7
• Signs of sepsis are present 6

Antibiotics are NOT routinely indicated for acute watery diarrhea 3, 5, 7

Adjunctive Therapies

• Probiotics may be offered to reduce symptom severity and duration in immunocompetent patients 3, 4, 5
• Zinc supplementation (for children 6 months-5 years in high zinc-deficiency areas or with malnutrition) reduces diarrhea duration 3, 4

ORS Selection and Common Pitfalls

Use ORS containing 75-90 mEq/L sodium for active rehydration 4

• When purging rate is very high (>10 mL/kg/hour), solutions with 75-90 mEq/L sodium are mandatory 4
• For maintenance, use 40-60 mEq/L sodium solutions 4
• When using fluids with >60 mEq/L sodium for maintenance, supplement with low-sodium fluids (breast milk, formula, or water) to prevent sodium overload 4

Critical pitfalls to avoid:

• Do NOT use cola, apple juice, sports drinks, or soft drinks for rehydration—they contain inadequate sodium and excessive sugar, worsening osmotic diarrhea 1, 3
• Do NOT allow thirsty patients to drink large volumes of ORS ad libitum—this worsens vomiting 4
• Do NOT mix ORS packets with inappropriate volumes of water—provide detailed written and oral instructions 3, 4

Reassessment and Warning Signs

Reassess hydration status after 2-4 hours of rehydration: 1, 3, 4

• If rehydrated, transition to maintenance phase with ongoing loss replacement 1, 4
• If still dehydrated, reassess fluid deficit and restart rehydration protocol 3

Instruct patients/caregivers to return immediately if: 1, 3, 4

• Many watery stools continue or high stool output (>10 mL/kg/hour) persists 1, 4
• Bloody diarrhea develops 4
• Intractable vomiting occurs 1, 4
• Fever develops or worsens 3
• Decreased urine output, lethargy, or irritability occurs 3, 4
• Condition worsens overall 3

Prevention

Hand hygiene is critical: 3, 4

• After toilet use and diaper changes 3, 4
• Before and after food preparation 3, 4
• Before eating 3, 4
• After handling garbage or animals 4

Keep ORS sachets at home and begin administration at the first sign of diarrhea 3