What is the workup and recommended treatment for a 9-year-old with suspected gastroenteritis?

Management of Suspected Gastroenteritis in a 9-Year-Old

For a 9-year-old with suspected gastroenteritis, give oral rehydration solution (like Pedialyte) as the primary treatment, continue regular foods once rehydrated, and consider ondansetron if vomiting prevents drinking. 1, 2

Workup: What to Check

Most children with gastroenteritis need minimal or no testing. 3

Clinical Assessment

• Check hydration status by examining: skin turgor (pinch test), mucous membranes (dry mouth), mental alertness, capillary refill (press fingernail), heart rate, and urine output 1, 2
• Classify dehydration severity: mild (3-5% body weight loss), moderate (6-9%), or severe (≥10%) based on these physical signs 1
• Ask about fluid intake and output - if the child is drinking normally and urinating regularly with no vomiting, significant dehydration is unlikely 3

Laboratory Testing

• No lab tests are needed for typical viral gastroenteritis with mild symptoms 3
• Consider stool testing only if: bloody diarrhea, recent travel, recent antibiotics, suspected food poisoning, or immunocompromised 1
• Blood tests are generally not necessary unless severe dehydration is present 3, 4

Treatment Plan

Rehydration (Most Important)

Oral rehydration solution (ORS) like Pedialyte is the first-line treatment for mild to moderate dehydration. 1, 2

• Give 50-100 mL/kg over 3-4 hours for initial rehydration 2
• Then give 120-240 mL of ORS after each diarrheal stool or vomiting episode (up to ~1 liter per day) 2
• Use commercial low-osmolarity ORS (Pedialyte, CeraLyte) - these are specifically designed for rehydration 2
• Avoid apple juice, Gatorade, soda, or sports drinks as primary rehydration - they contain too much sugar and wrong electrolyte balance, which can worsen diarrhea 1, 2

When IV Fluids Are Needed

• Reserve IV rehydration for: severe dehydration (>10%), shock signs, altered mental status, or failure of oral rehydration after trying ondansetron 1, 2
• Use isotonic fluids (normal saline or lactated Ringer's) at 20 mL/kg over 30 minutes if IV is needed 2

Feeding

Resume normal age-appropriate foods during or immediately after rehydration - do not withhold food. 1, 2

• Early feeding is better than fasting - it helps restore digestive function 1, 2
• Continue regular diet; restrictive diets like BRAT (bananas, rice, applesauce, toast) are unnecessary 1
• Avoid foods high in simple sugars (candy, soda, juice) as they can worsen diarrhea 1

Medications

Ondansetron (Zofran) can be given if vomiting is preventing oral rehydration - dose is 0.15 mg/kg 2

• This helps reduce vomiting, improves oral intake success, and decreases need for IV fluids 2, 5
• Can be given orally or IV 5

Do NOT give anti-diarrheal medications (like Imodium/loperamide) to children under 18 years - they are not safe and not effective 1, 2

Antibiotics are not needed for typical viral gastroenteritis 1

Simple Parent Education

What to Do at Home

"Give Pedialyte frequently in small amounts"

• Offer 2-4 ounces (60-120 mL) every 15-30 minutes 2
• If vomiting, wait 15 minutes then try again with smaller sips
• Continue until diarrhea and vomiting stop 1

"Feed your child normally once they can keep fluids down"

• Don't restrict diet - give regular foods 1, 2
• Continue breastfeeding if applicable 1

"What NOT to use"

• Don't use apple juice, Gatorade, or soda as the main rehydration drink 1, 2
• Don't give anti-diarrheal medicines like Imodium 1, 2

When to Return/Seek Care

Go to emergency department if:

• Child becomes very sleepy or confused 1, 2
• No urine for 8-12 hours 3
• Dry mouth, no tears when crying, sunken eyes 2
• Fast heart rate or breathing 2
• Blood in diarrhea 1
• Cannot keep down any fluids despite trying small amounts 1, 2

Prevention

"Wash hands frequently" - after bathroom, before eating, after diaper changes 1, 2

• Keep sick child home until 2 days after symptoms resolve 1
• Clean contaminated surfaces promptly 1

Key Pitfalls to Avoid

• Don't delay rehydration while waiting for test results - start Pedialyte immediately 1
• Don't use inappropriate fluids (juice, sports drinks) for moderate dehydration 1, 2
• Don't withhold food - early feeding improves outcomes 1, 2
• Don't give anti-diarrheal medications to children - they can cause serious complications 1, 2