Management of Vomiting, Diarrhea, and Fever
Immediate oral rehydration therapy is the cornerstone of management for patients presenting with vomiting, diarrhea, and fever, with oral rehydration solutions being as effective as intravenous fluids for most cases while avoiding the risks of IV therapy. 1
Initial Assessment
Obtain a focused history addressing:
- Duration and onset of symptoms (abrupt vs. gradual) 1
- Stool characteristics: frequency, volume, presence of blood, mucus, or pus 1
- Vomiting frequency and ability to tolerate oral fluids 1
- Fever presence and associated symptoms (abdominal pain, cramping, weakness) 1
- Dehydration signs: thirst, decreased urination, orthostatic symptoms, lethargy, decreased skin turgor, dry mucous membranes 1, 2
Physical examination should focus on:
- Vital signs: orthostatic pulse and blood pressure changes, fever 1
- Volume status: mucous membrane moisture, skin turgor, jugular venous pulsations 1
- Abdominal examination: tenderness, distension 1
- Mental status: altered sensorium may indicate severe dehydration 1
Rehydration Strategy
Oral Rehydration (First-Line)
Begin oral rehydration immediately using WHO-recommended solutions (Pedialyte, Ceralyte, or generic equivalents) 1. These solutions are superior to sports drinks or soft drinks, which have inadequate sodium and excessive osmolarity 3.
Dosing by age:
- Children <2 years: 50-100 mL after each loose stool 1
- Older children: 100-200 mL after each loose stool 1
- Adults: As much as desired, guided by thirst 1
For vomiting patients, oral rehydration remains feasible: give small frequent amounts (1 teaspoon every 1-2 minutes) 3. Consider ondansetron for children >4 years to facilitate oral intake, though it may increase stool volume 1.
Intravenous Rehydration
Reserve IV fluids for:
- Severe dehydration with shock or altered mental status 2
- Persistent vomiting preventing oral intake despite antiemetics 1
- Failed oral rehydration after adequate trial 4
Use isotonic solutions (lactated Ringer's or normal saline) 2.
Dietary Management
- Continue breastfeeding throughout illness 1
- Resume feeding early once rehydration begins—this shortens illness duration and improves outcomes 1
- Eliminate lactose-containing products temporarily, as this reduces diarrhea duration by approximately 18 hours 1
- Offer small, frequent meals: bananas, rice, applesauce, toast, plain pasta 1
- Avoid fatty, spicy foods, caffeine, and high-osmolar supplements 1
Antimotility and Antiemetic Agents
Loperamide
Do NOT give to children <18 years due to risk of serious adverse events including death 1. For adults with watery diarrhea, loperamide 4 mg initially, then 2 mg after each loose stool (maximum 16 mg/day) may be used 1. Avoid in any patient with fever or bloody diarrhea due to risk of toxic megacolon 1.
Ondansetron
May be given to children >4 years and adults to facilitate oral rehydration tolerance 1. This reduces immediate hospitalization needs but may increase stool volume 1.
Antimicrobial Therapy
Most infectious diarrhea is self-limiting and does not require antibiotics 2. Consider empiric antimicrobials only for:
- Severe illness with high fever and bloody stools 1
- Immunocompromised patients 1
- Suspected cholera in endemic areas 1
Fluoroquinolones are first-line when antibiotics are indicated 1.
When to Seek Medical Evaluation
Patients should seek immediate care if:
- No improvement within 48 hours 1
- Worsening symptoms or development of severe dehydration signs 1
- Persistent high fever 1
- Frank blood in stool 1
- Severe abdominal pain or distension 1
- Signs of sepsis (altered mental status, hypotension) 1
Critical Pitfalls to Avoid
- Do not withhold oral fluids for 24 hours—this outdated practice worsens outcomes 1
- Do not use antimotility agents in children or in any patient with fever/bloody diarrhea 1
- Do not rely on sports drinks alone for rehydration—they lack adequate sodium 3
- Do not delay rehydration while awaiting diagnostic testing 1
- Monitor electrolytes in severe cases, as hypokalemia and hyponatremia can occur 2, 5