Pseudomembranous Colitis

Question 1

Outline the pathophysiology of pseudomembranous colitis

Answer 1

• Broad-spectrum antibiotics disrupt normal bowel flora, allowing C. diff spores to activate and colonise
• Production of A and B toxins causes pseudomembrane formation and increased vascular permeability
• Symptoms occur generally at days 4-9 of antibiotic therapy

Question 2

What are the risk factors for pseudomembranous colitis?

Answer 2

• Antibiotic exposure (ampicillin, 2/3 cephalosporins, clindamycin, fluoroquinolones)
• Advanced age
• Hospitalisation
• C. diff disease history

Question 3

What are the likely findings on presentation in a patient with pseudomembranous colitis?

Answer 3

• Diarrhoea
• Abdominal pain
• Examination signs
• Low grade fever
• Abdominal tenderness

Question 4

How might you work-up a suspected case of psuedomembranous colitis?

Answer 4

• FBC (increased WBC)
• Stool immunoassay for toxins A and B
• Colonoscopy

Question 5

What are the management prinicples for pseudomembranous colitis?

Answer 5

• Remove causative agent
  
  • Discontinue all antibiotics if possible especially risky ones
• Antibiotic therapy
  
  • Metronidazole +/- vancomycin (if severe disease)
• Supportive care and infection control