What area of the intestine is most commonly affected by Clostridium difficile?

Clostridioides difficile Primarily Affects the Colon

Clostridioides difficile infection (CDI) primarily affects the colon, particularly causing inflammation and damage to the colonic mucosa. 1

Pathophysiology of C. difficile Infection

• C. difficile spores survive the acidic environment of the stomach and germinate in the intestine when the normal gut microbiota is disrupted, most commonly due to antibiotic use 2, 3
• The primary toxins produced by C. difficile (toxins A and B) act as glucosyltransferases that promote activation of Rho GTPases, leading to disorganization of the cytoskeleton of colonocytes and eventual cell death 3
• The resulting damage to the colonic mucosa causes a spectrum of disease severity, ranging from mild diarrhea to severe pseudomembranous colitis 1

Clinical Presentation and Manifestations

• CDI can present with varying degrees of severity, including:

  • Mild to moderate diarrhea
  • Colitis without pseudomembrane formation
  • Pseudomembranous colitis
  • Fulminant colitis with potentially life-threatening complications 1

• Additional symptoms may include:

  • Abdominal pain and cramping
  • Fever and rigors
  • Signs of severe systemic inflammatory response 1

Diagnostic Features

• Laboratory findings may include marked leukocytosis, elevated serum creatinine, and elevated serum lactate in severe cases 1

• Endoscopic findings in the colon may show:

  • Edema
  • Erythema
  • Friability
  • Ulceration
  • Pseudomembranes (yellow-white plaques on the colonic mucosa) 1

• CT imaging may demonstrate:

  • Colonic wall thickening
  • "Accordion sign"
  • "Double-halo" or "target sign"
  • Pericolonic fat stranding
  • Ascites 1

Epidemiology and Risk Factors

• C. difficile is the most common readily identifiable cause of infectious diarrhea in long-term care facility residents 3
• Rates of asymptomatic C. difficile colonization in long-term care facilities approach 10-30% 3
• Key risk factors include:
  • Antibiotic exposure (most important modifiable risk factor)
  • Advanced age (>65 years)
  • Hospitalization or residence in long-term care facilities
  • Comorbidities such as inflammatory bowel disease
  • Immunodeficiency
  • Gastrointestinal procedures 2

Treatment Approach

• For non-severe initial episodes, oral metronidazole 500 mg three times daily for 10 days may be sufficient 1
• For severe C. difficile colitis, oral vancomycin 125 mg four times daily for 10 days is recommended 1
• For fulminant C. difficile colitis, surgical consultation for potential colectomy may be necessary in cases of:
  • Colonic perforation
  • Systemic inflammation not responding to antibiotics
  • Toxic megacolon
  • Severe ileus 1

Important Clinical Considerations

• Avoid antiperistaltic agents and opiates as they can mask symptoms and potentially worsen disease 1
• In patients with inflammatory bowel disease, absence of pseudomembranes does not rule out C. difficile infection 1
• Serum lactate >5.0 mmol/L indicates severe disease and may guide timing of surgical intervention 1
• Continued use of antibiotics for other infections during C. difficile treatment significantly increases risk of recurrence 1

Prevention Strategies

• Rapid isolation of infected patients
• Contact precautions until resolution of diarrhea
• Hand hygiene with soap and water (alcohol-based sanitizers do not inactivate C. difficile spores)
• Thorough environmental cleaning and disinfection 2, 3