Acute gastroenteritis and infectious diarrhoea — structured clinical encounter

Station 1 — assessment and grading

Asked for my first impression, I explain that a toddler with two days of watery, non-bloody diarrhoea and vomiting has acute gastroenteritis, and that my priority is to grade his dehydration. His sunken eyes, dry mucosa, slow skin pinch and prolonged capillary refill in an alert child with warm peripheries place him in the some, or mild-to-moderate, dehydration group rather than shock. I would weigh him and compare with a recent well weight if available. [3] [4]

Station 2 — excluding the mimics

Asked what else I would consider, I state that vomiting and abdominal pain have dangerous mimics, so before committing to gastroenteritis I would examine the abdomen for distension, focal tenderness, a mass or absent bowel sounds, and ask specifically about bilious green vomiting, which would raise intussusception, malrotation with volvulus or obstruction. I would also consider a urinary tract infection, diabetic ketoacidosis and raised intracranial pressure, and check a glucose. The fact that diarrhoea is his dominant symptom supports gastroenteritis. [1] [3]

Station 3 — rehydration

To rehydrate him, I would use low-osmolarity oral rehydration solution at roughly fifty to one hundred millilitres per kilogram over four hours in small, frequent sips, then reassess. This is the treatment of choice for mild-to-moderate dehydration and is as effective as intravenous fluid with fewer complications. If he refuses or vomits repeatedly, I would give the solution by nasogastric tube rather than moving to a drip, and I would reserve intravenous 0.9 percent saline for shock or failed oral and nasogastric rehydration. [8] [1]

Station 4 — adjuncts and feeding

Asked about adjuncts, I would give a single dose of ondansetron to control the vomiting and enable oral rehydration, which reduces the need for intravenous fluids and admission. I would add zinc for ten to fourteen days where indicated, resume his normal age-appropriate feeds early without diluting them, and continue any breastfeeding. I would avoid antidiarrhoeal drugs such as loperamide in a child this young, and I would not send routine bloods or stool cultures in a well-perfused child with watery diarrhoea. [13] [5]

Station 5 — escalation, disposition and the family conversation

Finally I describe how I would escalate and safety-net. If he became lethargic, cold and poorly perfused I would treat severe dehydration or shock with an intravenous or intraosseous bolus of ten to twenty millilitres per kilogram of 0.9 percent saline and check electrolytes and glucose. Once he is rehydrated and drinking, I would discharge him with clear advice on continuing oral rehydration solution after each loose stool, resuming feeding, and returning if he cannot keep fluids down, passes less urine, becomes drowsy or develops blood in the stool. I would counsel the family that gastroenteritis is self-limiting and that keeping fluids in is what matters most. [14] [1]