Exam Cram

• Common question asks for which organisms +/- mx

• Causes of bloody diarrhoea- shigella, campylobacter, ecoli 0157

Background

Common MCQ asks for which organisms +/- mx

Toxins

1. Staph aureus

• Meat or dairy products

• Vomiting 0-12hrs after consumption

2. Bacillus ceres

• Rice

• Vomiting/ diarrhoea 

• Onset 1-6hrs, total 24hrs 

Infections

1. Giardiasis

• Presentation: travel hx, IBS symptoms, subacute, St. Petersberg river, steatorrhoea, weight loss

• Investigations: stool culture & sensitivity x3 (often falsely negative)

• Management: metronidazole or tinidazole

2. Shigella

• Highly infectious

• Watery diarrhoea with blood/ mucous, c. 3 days

• Associated with nursery children

• Azithromycin if severe symptoms/ immunocompromised

3. Norovirus

• Commonest source of gastro-enteritis in UK

• Presentation

  • 12-48hrs of projective vomiting, watery diarhoea

  • Very contagious, often sick contacts- e.g. cruise

• No blood in diarrhoea, can have mucous

• Transmitted: faecal oral route, contact or aerosol

4. Rotavirus

• Kids

5. Campylobacter

• Unwashed chicken

• Usually requires nil antibiotics

outline

Assessment

History:

• Diarrhea ?blood

• Vomiting

• Abdominal pain- colicky

• Fatigue, feverish

• Travel history/ sick contacts / recent diet 

Examination:

• Generalised abdominal tenderness

• Mild tachycardia, hypotension

Investigations

• Creatinine ?AKI

• Electrolytes

• Consider faeces stool culture, ova

Diagnosis

Diagnostic criteria: symptoms- diarrhea and vomiting highly specific for GE, 

• Stool culture can provide organism and sensitivities

Differentials

• Diarrhoea: IBD, diverticulitis, colitis

• Vomiting: perforation, gastritis

Categorised

1. By Organism- dictates antibiotics

2. By severity- level of dehydration

Management

1. Consider d/c home if tolerating PO fluids and symptom burden manageable

2. Admission indications

   1. 1. 1. IVF

         2. Replace electrolytes

         3. Not coping due to high symptom burden (particularly in elderly)

3. Consider antibiotics in severe cases

Med Reg Notes

References

Page written in 2024. 

Produced off FOAM basis: free, open access, medical education. This is not clinical advice, education for multiple choice questions only! 

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