Clostridioides (Clostridium) difficile infection - emergency medicine revision
At‑a‑glance (ED priorities)
- Suspect C. difficile in patients with new watery diarrhoea after recent antibiotics or in hospital/nursing‑home patients.
- Immediate actions: isolate (contact precautions), stop non‑essential systemic antibiotics, resuscitate (IV fluids/electrolytes), send unformed stool for C. difficile testing (follow local/UKHSA lab pathway), and avoid antimotility agents.
- Treat adults who require therapy with oral vancomycin 125 mg four times daily for 10 days (NICE NG199).
- Escalate early for severe or life‑threatening features and involve microbiology/gastroenterology/surgery (UKHSA/NICE).
Introduction
Clostridioides difficile is a spore‑forming, gram‑positive anaerobic bacillus. Disease occurs when toxin‑producing strains overgrow after disruption of normal gut flora (commonly following systemic antibiotics).
Toxin‑mediated mucosal injury produces a spectrum from mild diarrhoea to fulminant pseudomembranous colitis with toxic megacolon, perforation and sepsis. Early recognition, infection control and targeted therapy are the ED priorities (NICE NG199; UKHSA).
Pathogenesis and microbiology
- Pathogenic strains produce two main exotoxins:
- Toxin A (enterotoxin) - promotes secretion and inflammation.
- Toxin B (cytotoxin) - responsible for cytopathic mucosal damage and pseudomembrane formation.
- Disease follows disruption of normal flora (most commonly after broad‑spectrum antibiotics).