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Gastroenteritis and dehydration in children
In gastroenteritis the danger is dehydration, not the organism: the degree of dehydration is assessed clinically, most children are treated with oral rehydration solution (ORS), and feeding continues; antibiotics only in defined situations.
Why it matters in the exam
Questions present a child with diarrhoea and vomiting and ask about the degree of dehydration from the signs (capillary refill, skin turgor, deep breathing, level of consciousness), the right treatment (ORS, not juices or fizzy drinks) and the place of ondansetron, antidiarrhoeal drugs and antibiotics. A classic case: a toddler with bloody diarrhoea and a febrile seizure — Shigella.
Further traps: in bloody diarrhoea from Shiga-toxin-producing E. coli (STEC), antibiotics and antimotility drugs raise the risk of HUS; hypernatraemic dehydration is corrected slowly, because fast correction causes cerebral oedema; and feeding should not be stopped or formula diluted. Salmonella is not treated routinely — only in infants under 3 months, the immunosuppressed or bacteraemia.
In most children the cause is viral: rotavirus, norovirus and adenovirus. Bloody diarrhoea, high fever and severe abdominal pain point to a bacterial cause, and a stool culture is then sent. Remember also the conditions that mimic gastroenteritis: intussusception, appendicitis, DKA and UTI — vomiting without diarrhoea or a child who looks very ill should bring them to mind. Blood tests are not needed in mild dehydration, but are needed when an infusion is started.
Key points
- Assessing dehydration: capillary refill, skin turgor and breathing are the best signs.
- Mild to moderate: ORS 50–100 mL/kg over 4 hours; nasogastric tube before an infusion.
- Severe: a 20 mL/kg isotonic bolus.
- Continue breastfeeding and food; no juices, no loperamide.
- Antibiotics in Shigella and defined situations; not in STEC.
Summary table
| Degree | Signs | Treatment |
|---|---|---|
| None or mild (below 3%) | Alert, moist mucosa, normal capillary refill | Continue feeding; ORS after each stool |
| Moderate (3%–9%) | Thirsty, dry mucosa, capillary refill above 2 seconds, reduced skin turgor | ORS 50–100 mL/kg over 4 hours, in small frequent amounts; nasogastric tube if refused |
| Severe (10% or more) | Drowsy, fast weak pulse, deep breathing, prolonged capillary refill | Intravenous bolus of 20 mL/kg isotonic fluid, repeat as needed |
| Hypernatraemic | "Doughy" skin, irritability, high sodium | Slow correction over 48 hours; sodium fall of no more than 10 mmol/L per day |
| Antibiotics | Shigella, cholera, Salmonella in an infant under 3 months or the immunosuppressed | Not in STEC — risk of HUS |
A free exam question
בן 7 ( שנים שלוקה באנמיה חרמשית Sickle cell ) מאושפז עקב חום עד 39 מ"צ וצמיחה בדם של Salmonella spp. . איזו? בדיקת דימות מומלץ לבצע (the question as examined, in Hebrew)
- א. מיפוי כליות
- ב. אולטרסאונד בטן
- ג. מיפוי עצמות
- ד. צילום בית חזה
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Sources
- ESPGHAN/ESPID Evidence-Based Guidelines for the Management of Acute Gastroenteritis in Children in Europe, 2014 — Assessment of dehydration and rehydration
- WHO: The Treatment of Diarrhoea — A manual for physicians and other senior health workers, 4th revision (2005) — Assessment and treatment plans
- Nelson Textbook of Pediatrics, 22nd edition (2024) — Acute Gastroenteritis in Children
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.