Antibiotic associated c. diff diarrhoea

  • Candidate Instructions
  • Actor Instructions
  • Mark Sheet
  • Score

Location: You are an FY1 on the acute medical team

Patient: 50 year old patient has presented with profuse diarrhoea

– Take a focused history from the patient
– After 6 minutes you will be asked a series of questions by the examiner
– Answer any questions that the patient may have

Note to actor: Try to restrain yourself from volunteering too much information – you may do so when prompted (that is, by a specific question, not a general one). If a student is on the wrong line of clinical reasoning do not fuel this line of thinking, state no to the question as being ambiguous may prompt further questioning and does not allow the student to be appropriately tested. The aim of the exercise is to take a focused history; short answers are required.

You are a 50 year old patient who has attended the hospital with diarrhoea. You were recently seen in hospital and told to re-attend if you weren’t feeling any better.

The diarrhoea started 3 days ago but has become more severe over the last 24 hours. There is a large volume of watery diarrhoea. You have been passing stools about 20 times a day. You are struggling to eat and drink. You have had no nausea or vomiting. You have no abdominal pain.

You have not recently eaten out. You have no recent travel abroad. You have not been in contact with anyone who is unwell.

You were recently seen by the medical team in hospital and treated for a chest infection. You were discharged home with some oral antibiotics and you completed the course 3 days ago. On the last day of taking the antibiotics you started to have this diarrhoea.

You have not noticed any mouth ulcers, back pain or painful red eyes.

PMH – usually fit and well. Recently admitted and treated for chest infection. No previous operations.

DH – no regular medications. Recently completed a course of oral co-amoxiclav. You have no drug allergies

SH – you do not smoke or drink alcohol. You live at home with your partner


– You are worried that the diarrhoea is not stopping. You are feeling very weak as you have not been able to eat or drink. You just want to feel better so you can get back to your normal life.

If the candidate appears to have finished early remind them how long is left at the station and enquire if there is anything else they would like to ask, or whether they have finished. If they have finished, please remain silent and allow the candidate that time for reflection.

Category Question
Introduction Candidate appropriately introduced themselves with:
Full name
Clarifies who they are talking to
Asks patient for preferred name

History History
Stool consistency
Exacerbating factors
Relieving factors
Severity / impact on daily living

Associated features Associated features
Weight loss
Eating and drinking
Nausea / vomiting

Infective features Infective features
Contact with a person with diarrhoea
Explores possible sources of enteric infection - meals out / recent farm visit
Travel abroad — risk of infection increased if visit to region with poor hygiene standards

Red flag Red flag symptoms
Blood in the stool
Recent hospital treatment or antibiotic treatment
Persistent vomiting
Weight loss
Painless, watery, high-volume diarrhoea
Nocturnal symptoms disturbing sleep

Extra-intestinal features
Mouth ulcers
Painful red eye
Joint or back pain

GI systems review
Indigestion / reflux
Abdominal pain

PMH Past Medical History
Past medical history appropriately explored

DH Drug History
Drug history taken
Recently completed a course of co-amoxiclav
Drug allergies

SH Social History
Living situation

FH Family history
Family history appropriately explored

Explores ideas, concerns, expectations, feelings

Question What is your most likely diagnosis?
Antibiotic associated diarrhoea caused by C Diff

Question What are your differentials?
Infective - bacterial, viral, parasitic
Drug induced
Food allergy
Irritable bowel syndrome
Inflammatory bowel disease
Coeliac disease
Diverticular disease
Colorectal cancer

Question What investigations would you like to order?
Stool culture for c diff toxin
Blood cultures

Question How are you going to manage this patient?
Side room until results of stool culture
Oral metronidazole
IVF replacement & electrolytes as needed

The next day the patients abdomen appears distended, an abdominal x-ray is done. Please review this imaging and comment on your findings

Distended large bowel
Toxic mega colon

Question How would you manage this patient now?
ABCDE approach
NG tube
Surgical referral