History Taking · Foundation · Gastroenterology

Vomiting and Diarrhoea in a 34-Year-Old Woman

Practise this PLAB 2 history taking station on Viral Gastroenteritis. 8-minute voice AI simulation with feedback on all 3 marking domains.

Clinical scenario

You are an FY2 doctor in a GP surgery. Mrs Fiona Townsend, a 34-year-old woman, has come to see you with acute onset vomiting and diarrhoea starting yesterday evening. She appears unwell and dehydrated. Please take a focused history, assess her hydration status, and discuss management.

Background notes: PMH: Nil significant

What this station tests

  • Dehydration severity assessment: clinical signs (dry mucous membranes, skin turgor, postural symptoms) to determine community versus hospital management
  • Excluding serious causes through targeted history: no blood, no fever, no surgical signs, no recent antibiotics, no travel
  • OCP interaction with vomiting: additional contraception needed for 7 days after vomiting stops, commonly missed
  • Infection control: 48-hour exclusion from work after last episode of vomiting or diarrhoea
  • Oral rehydration technique: small frequent sips rather than large volumes, ORS sachets, avoiding dairy

How to use your 8 minutes

  • 0-1 min — Introduction: Introduce yourself, confirm identity, open question. 'What's brought you in today?'
  • 1-4 min — Systematic History: Presenting complaint detail (SOCRATES for pain, timeline, severity). Systems review. PMH, medications, allergies.
  • 4-6 min — Context and ICE: Social history (smoking, alcohol, occupation, living situation). Family history. Ideas, Concerns, Expectations.
  • 6-7 min — Summary and Plan: Summarise findings back to patient. Share differential/working diagnosis. Outline investigation and management plan.
  • 7-8 min — Closing: Safety netting with specific red flags. Arrange follow-up. Check for questions.

Consultation approach

The opening

Acute gastroenteritis stations test the candidate's ability to assess dehydration severity, exclude serious causes, and provide practical management advice. Most cases are self-limiting, but the candidate must identify the patients who need more than reassurance. Mrs Townsend is 34, presenting with 18 hours of vomiting and diarrhoea. She appears unwell and dehydrated. Open with: 'Mrs Townsend, tell me what happened and how you are feeling right now.' Current symptoms matter more than detailed onset history.

Core approach

Assess the illness. Sudden onset yesterday evening: vomiting 5 to 6 times, watery diarrhoea 7 to 8 times overnight. Initially food content, now bilious. No blood in vomit or stool. No fever (checked). Generalised abdominal discomfort, no focal tenderness. She feels weak, light-headed on standing, and has a dry mouth. She can tolerate small sips of water but larger volumes trigger nausea.

Assess dehydration. Dry mucous membranes, reduced skin turgor (check), light-headed on standing (postural symptoms). No signs of severe dehydration (conscious, oriented, perfusing). This is mild to moderate dehydration manageable in the community with oral rehydration.

Exclude serious causes. No bloody diarrhoea (excludes most invasive bacterial causes). No high fever (makes bacterial enteritis less likely). No severe abdominal pain or rigidity (excludes surgical abdomen). No recent antibiotics (excludes C. diff). No recent travel (excludes tropical infections). Her sister visited recently and was unwell, making person-to-person viral transmission likely. Her husband ate the same lasagne and is well (makes food poisoning less likely).

Check medications: she takes the combined oral contraceptive pill. Vomiting can reduce OCP efficacy. This is a commonly missed counselling point. She should use additional contraception for 7 days after vomiting stops, or follow the missed pill rules.

Closing and safety netting

Management is supportive. Oral rehydration: small, frequent sips (not large volumes), ORS sachets if available, or flat lemonade/diluted squash. Avoid dairy until settled. Resume eating with bland foods when appetite returns. Paracetamol for abdominal discomfort. Anti-emetics: consider short course of cyclizine or ondansetron if vomiting is preventing oral rehydration.

Address her concerns: she is worried about missing her project deadline. Advise 48 hours off work after last episode of vomiting or diarrhoea (infection control). Address the OCP: additional contraception for 7 days after vomiting resolves.

Safety net: 'Come back or call 111 if you cannot keep any fluids down for more than 24 hours, you develop blood in your stool or vomit, you become confused or very drowsy, you develop a high fever, or your symptoms are not improving after 48 hours.' No antibiotics needed for viral gastroenteritis.

How examiners mark this station

Examiners will focus on the thoroughness and structure of your history taking for viral gastroenteritis. Domain 1 (Data Gathering) carries the most weight: expect marks for systematic coverage of presenting complaint, red flags, PMH, medications, social and family history. Domain 2 (Clinical Management) requires a clear differential, appropriate investigations, and a safe management plan with safety netting. Domain 3 (Interpersonal Skills) is assessed throughout: genuine exploration of ICE, active listening, empathic responses, and clear communication without jargon.

Domain 1: Data Gathering, Technical and Assessment Skills (Primary focus)

Scores well: Dehydration assessed clinically. Serious causes excluded (no blood, no fever, no surgical signs). Contact history identified (sister). Medication check including OCP. Timeline and trajectory established.

Costs marks: Not assessing dehydration. Not excluding serious causes. Not checking medications.

Domain 2: Clinical Management Skills (Primary focus)

Scores well: Appropriate community management with oral rehydration. Anti-emetic considered. OCP counselling. 48-hour work exclusion. Clear safety netting with specific return criteria. No inappropriate antibiotics.

Costs marks: Prescribing antibiotics. Not advising ORS. Missing OCP interaction. No work exclusion advice.

Domain 3: Interpersonal Skills (Throughout)

Scores well: Addressing work concern practically. OCP advice delivered sensitively. Reassuring about self-limiting nature. Practical and specific advice she can act on immediately.

Costs marks: Dismissing her work concern. Not providing practical rehydration guidance. Being vague about recovery timeline.

Common examiner feedback (and how to fix it)

Did not gather sufficient information to make an adequate assessment of the patient's condition

Fix: Use a consistent framework for every history. After covering the presenting complaint, systematically move through PMH, drug history, social history, family history, and ICE. Keep a mental checklist.

Did not identify the patient's problems and/or did not develop a management plan adequately

Fix: Reserve the final 2 minutes to summarise your findings, share your working diagnosis with the patient, and outline your investigation and management plan including safety netting.

Common mistakes in this station

  1. Not checking her contraception. She takes the combined OCP. Vomiting reduces absorption and efficacy. Candidates who do not mention additional contraception miss a patient safety point.
  2. Prescribing antibiotics for viral gastroenteritis. No blood, no fever, no travel, clear viral contact history. Antibiotics are not indicated and candidates who prescribe them demonstrate inappropriate antibiotic use.
  3. Not advising the 48-hour exclusion from work. This is an infection control requirement. Candidates who say 'go back when you feel better' without specifying the 48-hour rule after last episode miss a public health point.

Resitting PLAB 2?

If you have previously struggled with history taking stations, focus on building a consistent systematic framework that you apply to every case. Practise structuring your history into clear phases (presenting complaint, systems review, PMH, social, ICE) so that even under pressure, you cover all domains. Many resitters lose marks not on knowledge but on organisation and time management.

Example opening

Good morning/afternoon, my name is Dr [Name], I'm one of the doctors here today. Could I confirm your name and date of birth please? Thank you. So, what's brought you in to see me today?

Frequently asked questions

How do I approach the consultation in this viral gastroenteritis station?

Acute gastroenteritis stations test the candidate's ability to assess dehydration severity, exclude serious causes, and provide practical management advice. Most cases are self-limiting, but the candidate must identify the patients who need more than reassurance. Mrs Townsend is 34, presenting with 18 hours of vomiting and diarrhoea.

What does a strong performance look like to the examiner in this station?

Strong performances show: Dehydration assessed clinically. Serious causes excluded (no blood, no fever, no surgical signs). Contact history identified (sister). Medication check including OCP. Weak performances: Not assessing dehydration. Not excluding serious causes. Not checking medications.

What is the biggest pitfall in this viral gastroenteritis station?

Not checking her contraception. She takes the combined OCP. Vomiting reduces absorption and efficacy. Another frequent error: Prescribing antibiotics for viral gastroenteritis. No blood, no fever, no travel, clear viral contact history.

How should I prepare for viral gastroenteritis if I have never seen it in practice?

Structure beats experience here. Focus on excluding serious causes through targeted history: no blood, no fever, no surgical signs, no recent antibiotics, no travel. The written guidance on this page covers the full approach, and practising the consultation aloud builds the fluency the examiner is listening for.

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