Acute Gastroenteritis in Children – Evidence‑Based Management

Assessment of Dehydration

Clinical examination remains the cornerstone for determining hydration status, guiding whether oral or intravenous therapy is needed. Signs such as reduced skin turgor, dry mucous membranes, oliguria, and altered mental status indicate mild‑to‑moderate dehydration, whereas shock signs (poor perfusion, weak pulse, altered consciousness) denote severe dehydration. 1
In hypernatremic children, classic dehydration signs may be masked, requiring heightened clinical vigilance. 1

The first‑line treatment is low‑osmolarity oral rehydration solution (ORS) given at 50–100 mL/kg over 3–4 hours, followed by ongoing replacement of losses. 1
Commercial ORS products (e.g., Pedialyte, CeraLyte, Enfalac Lytren) are recommended; fruit juices, sports drinks, and soft drinks should be avoided because they do not provide appropriate electrolyte balance. 1
Ongoing loss replacement:
- Children < 10 kg – 60–120 mL ORS per diarrheal stool or vomiting episode (≈ ≤ 500 mL/day). 1
- Children > 10 kg – 120–240 mL ORS per episode (≈ ≤ 1 L/day). 1

More than 90 % of children can be successfully rehydrated orally despite vomiting when ORS is offered in small, frequent aliquots (5–10 mL every 1–2 minutes) via spoon, syringe, or cup. 2
Allowing children to drink large volumes ad libitum increases the risk of further vomiting; small, frequent doses are essential. 2
If oral intake is not tolerated, nasogastric tube administration of ORS is an acceptable alternative for moderate dehydration. 1

Initial therapy consists of isotonic crystalloid (lactated Ringer’s or normal saline) boluses of 20 mL/kg, repeated until pulse, perfusion, and mental status normalize. 1
In malnourished infants, smaller boluses (10 mL/kg) given more frequently are advised because of reduced cardiac reserve. 1
After hemodynamic stabilization, transition to ORS to replace remaining fluid deficits; IV fluids are discontinued once the child is awake, has no aspiration risk, and bowel sounds return. 1

Age‑appropriate normal diet should be resumed immediately after rehydration is complete. 1
Breastfed infants continue nursing without interruption; formula‑fed infants receive regular lactose‑containing formula—dilution offers no benefit. 1
For older children, offer bland, starchy foods (rice, potatoes, noodles, crackers, bananas), cereals, soups, yogurt, vegetables, and fresh fruit every 3–4 hours; avoid foods high in simple sugars or fat (soft drinks, undiluted apple juice, Jell‑O, presweetened cereals). 3

Hospital admission is reserved for children who cannot be rehydrated orally despite anti‑emetic use, those with severe dehydration/shock, altered mental status, ileus (absent bowel sounds), or ketonemia requiring initial IV hydration to enable oral intake. 1

Empiric antibiotics are not recommended for routine acute gastroenteritis; they should be limited to high‑risk scenarios such as suspected bacterial infection in infants < 3–6 months, immunocompromised patients, sepsis, or outbreaks in institutional settings. 4
Antibiotics are specifically contraindicated for non‑Typhi Salmonella and Shiga‑toxin‑producing E. coli unless there is a clear risk of systemic infection or prolonged disease. 4

Do not withhold food or use prolonged diluted formulas, as this leads to therapeutic starvation and worsens nutritional outcomes. 3
Do not substitute popular beverages (fruit juices, sports drinks, sodas) for ORS in rehydration. 1
Do not permit ad libitum drinking in vomiting children; use small, frequent volumes instead. 2
Do not order routine stool cultures or laboratory tests when viral gastroenteritis is the most likely diagnosis. [no citation – omitted]
Do not prescribe antibiotics empirically unless the specific high‑risk criteria are met. 4

Ondansetron can be given to children > 4 years with acute gastroenteritis‑related vomiting to improve tolerance of oral rehydration; it may increase stool volume but reduces the immediate need for hospitalization or intravenous rehydration. 5
While ondansetron facilitates oral rehydration, it does not decrease 72‑hour hospitalization rates and may be associated with increased diarrhea. 5

Loperamide is contraindicated in all patients < 18 years with acute diarrhea; mortality has been reported in 0.54 % of children who received the drug (all < 3 years), with serious adverse events including ileus, abdominal distension, and lethargy. 5

Resuming an age‑appropriate normal diet immediately after rehydration decreases intestinal permeability, shortens illness duration, and improves nutritional outcomes; prolonged fasting worsens the malnutrition‑diarrhea cycle. 5

For febrile patients at risk of dehydration, the CDC recommends using low‑osmolarity oral rehydration solutions containing 45–90 mEq/L of sodium—with 40–60 mEq/L for maintenance therapy and 75–90 mEq/L for rehydration therapy【6】.