Clostridium difficile (or Clostridioides difficile) infection (C. diff)

Recognition, testing, modern treatment, and prevention of recurrence

What is C. diff?

C. diff is a bacterium that can cause antibiotic-associated diarrhoea and colitis, ranging from mild to severe colitis, sepsis, toxic megacolon, and death.

Who is at risk?

Recent antibiotic use
Hospital/healthcare exposure
Age over 65
Immunosuppression
Prior C. diff
Gastric acid suppression with proton pump inhibitors (PPIs) such as omeprazole, pantoprazole, esomeprazole (Nexium)

Typical symptoms

Watery diarrhoea (often ≥3 loose stools/day)
Lower abdominal pain/cramping
Fever, nausea, dehydration

Testing

Test only if diarrhoea is present and suspicion is high
Do not test formed stool or asymptomatic patients
PCR may detect colonisation; interpret with symptoms

Treatment (modern approach)

First-line: oral vancomycin or fidaxomicin (lower recurrence where available)
Not first-line: metronidazole (only if first-line unavailable and mild disease under supervision)

Supportive care

Hydration is essential
Avoid anti-diarrhoeal agents (e.g. loperamide)
Stop unnecessary antibiotics if possible

Recurrence

Recurs in up to 20–30%. Risk factors: age, continued antibiotics, immunosuppression. Specialist-directed strategies may include extended regimens or faecal microbiota transplantation in selected cases.

Prevention

Use antibiotics only when indicated
Handwashing with soap and water (spores)

When to seek urgent care

Worsening abdominal pain
Fever
Signs of dehydration
Reduced urine output
Abdominal distension
Confusion or collapse

Key takeaway: Any diarrhoea after recent antibiotics should raise concern for C. diff. Early recognition and correct treatment save lives.