What is the best course of action for a 22-year-old male patient with a 2-day history of diarrhea, currently experiencing 5 episodes of greenish, watery stools, who was previously prescribed medication and oral rehydration solution (ORS)?

Management of Acute Watery Diarrhea in a 22-Year-Old Male

Continue oral rehydration solution (ORS) and monitor closely without empiric antibiotics, as this patient has acute watery diarrhea without fever, blood in stool, or signs of severe dehydration—conditions where antimicrobial therapy is not indicated. 1

Immediate Assessment

Physical examination is unremarkable, indicating no severe dehydration. The key clinical indicators to confirm this assessment include:

• Normal skin turgor, moist mucous membranes, normal mental status, normal pulse rate, and adequate capillary refill 2
• Absence of signs requiring immediate IV therapy (shock, altered mental status, severe dehydration ≥10% fluid deficit) 1

Primary Treatment Strategy

ORS remains the cornerstone of management for this patient:

• Reduced osmolarity ORS is first-line therapy for mild to moderate dehydration in adults with acute diarrhea from any cause 1
• The patient should continue ORS to replace ongoing losses: 10 ml/kg for each watery stool 2
• Continue maintenance fluids until diarrhea resolves 1

Why Antibiotics Are NOT Indicated

Empiric antimicrobial therapy is not recommended for this patient because: 1

• He has acute watery diarrhea without recent international travel 1
• No fever is documented 1
• No blood in stool (dysentery) 2
• He is immunocompetent (22-year-old with no mentioned immunocompromise) 1
• Duration is only 2 days—antibiotics should be avoided in watery diarrhea lasting <14 days 1

Antimotility Agents

Loperamide may be offered to this adult patient since:

• He is ≥18 years old and immunocompetent with acute watery diarrhea 1
• No fever or bloody diarrhea present (which would contraindicate use) 1
• Dosing: 4 mg initial dose, then 2 mg after each unformed stool, maximum 16 mg daily 3

However, antimotility agents are not a substitute for fluid and electrolyte therapy and should only be used once adequate hydration is achieved 1

Dietary Management

Resume normal age-appropriate diet immediately:

• Do not withhold food 1
• Normal diet should be continued during or immediately after rehydration 1, 4

Adjunctive Therapies to Consider

Probiotics may be offered to reduce symptom severity and duration in this immunocompetent adult with infectious diarrhea 1

Warning Signs Requiring Escalation

Instruct the patient to return immediately if:

• Bloody diarrhea develops (dysentery) 2
• High fever develops 1
• Signs of severe dehydration appear (decreased urine output, lethargy, inability to tolerate oral fluids) 2, 4
• Diarrhea persists beyond 5 days 2
• Stool output exceeds 10 ml/kg/hour 2
• Intractable vomiting prevents oral rehydration 2

Expected Clinical Course

Clinical improvement is usually observed within 48 hours of appropriate ORS therapy 3. The change from yellowish to greenish stool and reduction from >10 to 5 episodes suggests the patient is already improving, which supports continuing conservative management 1.

Key Clinical Pitfall to Avoid

Do not prescribe antibiotics empirically for uncomplicated acute watery diarrhea. The strong recommendation against empiric antimicrobials in this setting is based on the risk of promoting antimicrobial resistance, potential adverse effects, and lack of benefit in self-limited viral or non-invasive bacterial gastroenteritis 1. Antimicrobial treatment should only be modified or initiated when a clinically plausible organism requiring treatment is identified 1.