What is the recommended treatment for a patient presenting with diarrhea?

Treatment of Diarrhea in Adults

For otherwise healthy adults with acute diarrhea, start loperamide 4 mg initially followed by 2 mg after each loose stool (maximum 16 mg daily) while maintaining adequate fluid intake with glucose-containing drinks or oral rehydration solutions. 1

Initial Assessment and Risk Stratification

Determine whether the patient requires self-management versus urgent medical evaluation by assessing for warning signs:

• High fever (>38.5°C) or frank blood in stools (dysentery) - requires medical supervision 2
• Severe vomiting that could lead to rapid dehydration 2
• Signs of dehydration (poor skin turgor, dry mucous membranes, altered mental status) 1
• Immunocompromised status, severe systemic illness, or age >75 years - direct to physician 2
• Symptoms lasting >7 days with no improvement 1

Patients without these warning signs can safely self-treat if they are previously healthy, over 12 years old, and experiencing sudden onset of loose/watery stools. 2

Fluid and Electrolyte Management

Mild to Moderate Dehydration

• Use reduced osmolarity oral rehydration solution (ORS) containing 65-70 mEq/L sodium and 75-90 mmol/L glucose as first-line therapy 2, 1
• Glucose-containing drinks (lemonades, sweet sodas, fruit juices) or electrolyte-rich soups are acceptable alternatives for mild cases 2
• Maintain fluid intake of 2200-4000 mL/day, guided by thirst and ongoing losses 2
• Standard ORS is preferred over sports drinks, juices, or soft drinks, which have suboptimal electrolyte composition 3

Severe Dehydration (Grade 3-4)

• Initiate intravenous rehydration with isotonic saline or balanced salt solution 2
• Fluid administration rate must exceed ongoing losses (urine output + 30-50 mL/h insensible losses + gastrointestinal losses) 2
• Transition to oral rehydration once patient can tolerate 2

Critical pitfall: Avoid overhydration in elderly patients with heart or kidney failure. 2

Pharmacological Treatment

Antimotility Agents

• Loperamide is the drug of choice: 4 mg initial dose, then 2 mg after each loose stool, not exceeding 16 mg daily 1
• Other antidiarrheal agents are not recommended due to uncertain efficacy, delayed onset, or adverse effects 2
• Contraindications for loperamide: 4
  • Bloody or febrile diarrhea (risk of toxic megacolon)
  • Pediatric patients <2 years (respiratory depression and cardiac toxicity)
  • Patients taking QT-prolonging drugs
  • Patients with cardiac arrhythmias or long QT syndrome

Antiemetics

• Ondansetron may be used in patients >4 years with vomiting to facilitate oral rehydration tolerance 1

Octreotide

• Consider for persistent diarrhea despite loperamide or severe grade 3-4 diarrhea: 100-150 μg subcutaneously three times daily 1

Dietary Management

• Continue eating solid food guided by appetite; there is no evidence that food intake affects recovery 2
• Small, light meals are recommended 2
• Avoid fatty, heavy, spicy foods and caffeine (including cola drinks) 2
• Consider avoiding lactose-containing foods (milk) in prolonged episodes 2
• Resume normal age-appropriate diet once rehydration is achieved 1

Antimicrobial Therapy

Empiric antibiotics are NOT routinely recommended for acute watery diarrhea in immunocompetent adults. 1

Indications for Antibiotics

• Moderate to severe traveler's diarrhea 2
• Diarrhea with fever and/or bloody stools 2
• Severe inflammatory diarrhea in immunocompromised patients 1
• Specific identified pathogens (Shigella, Campylobacter, C. difficile, protozoal infections) 5

Quinolones are the preferred antimicrobials for traveler's diarrhea, with cotrimoxazole as second choice. 2

When to Seek Medical Attention

Patients should seek medical evaluation if:

• No improvement within 48 hours 2
• Symptoms worsen or overall condition deteriorates 2
• Development of warning signs: severe vomiting, dehydration, persistent fever, abdominal distension, or frank blood in stools 2
• Signs of severe dehydration, grade 3-4 diarrhea, sepsis, or immunocompromised status with persistent symptoms 1

Special Considerations

Probiotics

• Not recommended for early treatment of acute diarrhea in adults due to insufficient evidence 2
• May shorten duration of illness in some cases 5

Diagnostic Testing

• Reserve stool cultures and testing for patients with severe dehydration, bloody stools, persistent fever >7 days, immunosuppression, or suspected nosocomial infection 1, 6
• Most cases of acute viral gastroenteritis do not require laboratory workup 5