What is the appropriate management for a patient presenting with diarrhea, abdominal pain, vomiting, and fever?

Management of Acute Gastroenteritis in a 20-Year-Old

For this 20-year-old with fever (101°F), 5 episodes of diarrhea, vomiting, and abdominal pain, you should immediately assess hydration status and initiate oral rehydration solution (ORS) while considering empiric antibiotics given the presence of fever. 1

Immediate Assessment

Evaluate hydration status by checking for:

• Orthostatic hypotension 2
• Skin turgor and dry mucous membranes 2
• Mental status changes 2
• Weakness and urine output 2

Classify the diarrhea as complicated or uncomplicated:

• This patient has complicated diarrhea due to fever, vomiting, and abdominal pain 3, 2
• Fever ≥38.5°C (101°F) is a specific indication for empiric antimicrobial therapy in young adults with acute diarrhea 1

Rehydration Strategy

For mild-to-moderate dehydration:

• Start reduced osmolarity ORS immediately as first-line therapy 1
• Administer small, frequent volumes (5 mL every minute) initially due to vomiting 3
• Use a spoon or syringe with close supervision to guarantee gradual progression 3
• Replace ongoing stool and vomit losses with appropriate volumes of ORS 3

For severe dehydration (if pulse is weak, perfusion poor, or mental status altered):

• Administer isotonic IV fluids (lactated Ringer's or normal saline) until pulse, perfusion, and mental status normalize 1
• Then transition to ORS for remaining deficit replacement 1

Antimicrobial Therapy

Given the fever of 101°F, empiric antibiotics should be considered 1:

• Fluoroquinolones are the recommended first-line agents 3
• This is an exception to the general rule that empiric antimicrobials are not recommended for acute watery diarrhea 1
• The presence of fever with diarrhea suggests possible bacterial etiology requiring treatment 3

Before starting antibiotics, obtain:

• Complete blood count 3
• Stool work-up for blood, Clostridium difficile, Salmonella, E. coli, and Campylobacter 3
• Electrolyte profile 3

Critical caveat: If STEC (Shiga toxin-producing E. coli) is suspected or confirmed, avoid antimicrobials as they increase risk of hemolytic uremic syndrome 1

Symptomatic Management

Loperamide can be used in this immunocompetent adult:

• Initial dose: 4 mg, followed by 2 mg every 4 hours or after every unformed stool 3, 2
• Maximum: 16 mg/day 3, 2
• However, avoid if bloody diarrhea develops due to risk of toxic megacolon 1

For vomiting:

• Antiemetic agents may facilitate oral rehydration 1
• Simultaneous correction of dehydration often lessens vomiting frequency 3

Dietary Management

Resume age-appropriate diet immediately upon rehydration 1:

• Continue usual diet during diarrhea 3
• Recommended foods: starches, cereals, yogurt, fruits, vegetables 3
• Avoid foods high in simple sugars and fats 3
• Eliminate lactose-containing products temporarily 3

Do not withhold food during the diarrheal episode—this is a common pitfall 1

Monitoring and Follow-Up

Hospitalization criteria (if any develop):

• Severe dehydration not responding to ORS 1
• Persistent vomiting preventing oral intake 3
• Signs of sepsis or shock 3
• Altered mental status 1

Modify or discontinue antimicrobials when specific pathogen is identified 1

If diarrhea persists beyond 48 hours despite treatment, consider further investigation 2

Key Pitfalls to Avoid

• Do not neglect rehydration while focusing on antimicrobial therapy 1, 2
• Do not use antimotility agents if bloody or inflammatory diarrhea develops 1
• Do not use antimicrobials if STEC infection is confirmed 1
• Do not withhold food during illness 1