Acute diarrhoea — KFP-style written assessment

KFP 1 (10 marks)

Four of eight guests at a 50th birthday dinner develop vomiting within four hours, followed by cramping diarrhoea overnight. The chicken dish is suspected. The first patient calls your practice: no blood, no fever, mild thirst, reduced urine output.^[3]

1. What is the likely diagnosis and what management do you advise? (4) ^[3]
2. Which assessment framework quantifies her dehydration, and why is it better than gestalt? (3) ^[2]
3. Should she take loperamide? (3) ^[4]

Model answers

1. Foodborne toxin-mediated gastroenteritis (Staph aureus or B. cereus for the rapid vomiting onset; C. perfringens for the overnight diarrhoea) — the shared meal with multiple affected guests is the signature. Management: oral rehydration solution in small frequent volumes, rest, and safety-netting for blood, fever or inability to keep fluids down. No antibiotics, no stool culture for this self-limiting pattern. ^[3]
2. The NIRUDAK clinical decision support tool validated for older children and adults: ordinal correlation 0.74 (simplified score 0.75) versus 0.64 for WHO guidelines, and WHO inter-rater reliability was poor (ICC 0.56 versus 0.98 for CDST). Clinical gestalt performs poorly; structured assessment of eyes, tears, mucous membranes, thirst and haemodynamics reduces both undertreatment and overtreatment. Her mild thirst with reduced urine output suggests mild-to-moderate dehydration manageable orally. ^[2]
3. Not first-line. In adult infectious diarrhoea, meta-analysis found racecadotril superior to loperamide — racecadotril is antisecretory (enkephalinase inhibition) without suppressing gut motility, so it does not retain invasive organisms. If symptom control is genuinely needed in this afebrile, non-bloody presentation, either agent short-term is defensible; loperamide is avoided whenever fever or blood suggests invasiveness. ^[4]