Synopsis
Distinguish acute infection, medication effects, overflow, inflammation and anatomy-related diarrhoea in surgical patients, measuring losses and acting early on dehydration, obstruction or toxic colitis.
- Measure stool or stoma volume, fluid intake, urine output and weight; frequency alone does not quantify loss.
- Resuscitate hypotension, oliguria and acute kidney injury while replacing sodium, potassium and magnesium deficits.
- Use recent antibiotics, healthcare contact, travel and immune status to choose targeted stool tests and isolation.
Key red flags
Hypotension, severe dehydration, peritonism, ileus, toxic dilatation, blood with systemic toxicity or high-output stoma losses require urgent assessment and cause-directed resuscitation.
Investigation priorities
quantify dehydration, perfusion and acid-base consequences
Management branches
Five days after ileal resection, an adult has 2.5 litres of stoma output, thirst, oliguria and rising creatinine. The team must quantify losses, replace fluid and electrolytes, review anatomy and exclude postoperative sepsis or obstruction.
- Recognise high-output dehydration from 2.5 litres of ileostomy loss, thirst, oliguria and rising creatinine; obtain intravenous access and give balanced isotonic crystalloid boluses with frequent reassessment while replacing measured ongoing loss.
- Confirm the remaining small-bowel and ileal length, stoma type, oral intake and medicines, and examine for obstruction, intra-abdominal sepsis and active enteritis before any antimotility drug.
Key medicines
St Mark’s oral rehydration solutionDissolve 20 g glucose, 3.5 g sodium chloride and 2.5 g sodium bicarbonate in water to a final volume of 1 litre, prepare fresh daily and sip the prescribed volume through the day after specialist assessment.Monitor renal function, sodium, potassium, magnesium, weight, urine and stoma output. This is not a substitute for intravenous resuscitation in shock, and fluid restriction or antimotility medicines require individual specialist instruction after obstruction and sepsis are excluded.