1. Background

• toxigenic Clostridium difficile is a gram positive obligate anaerobic bacillus
  • is part of the normal bowel flora & is present in 50-70% of asymptomatic neonates, 20-50% of infants, & 3% of adults
  • is not an invasive micro-organism
  • produces an exotoxin which subsequently produces a pseudomembranous colitis and diarrhea

2. Etiology

• antibiotic therapy may:
  1. suppress the bacterial flora of the bowel which normally prevents the growth of C. difficile and thus predisposes the gut to C. difficile overgrowth
  2. stimulate C. difficile to produce the exotoxin
• symptoms usually begin during antibiotic therapy (days 4-8) but may be delayed for as long as 21 days after the antibiotics have been discontinued
• relapses occur in 10-20% of cases despite appropriate therapy and respond to retreatment with vancomycin or metronidazole; there is no active immunization

1. Stool

• culture - CCFA medium (cycloserine, cefoxitin, fructose, agar)
• toxin assays - ELISA or latex agglutination to toxins A or B
  • toxin B cytotoxic to cultured fibroblasts within
  • 4-24 hours of infection

2. Colonoscopy

• characteristic pseudomembranous nodules or plaques in the rectum, sigmoid, and distal colon (rarely cecum or transverse colon)
• lesions are grayish-white exudates which are poorly adherent and surrounded by an edematous and erythematous inflammatory reaction

3. Serum

• dehydration
• hypoalbuminemia
• hypoproteinemia

1. Supportive

• oral rehydration fluid (ORF) or IV rehydration
• discontinue antibiotic or correct underlying disorder
  • mild cases - marked improvement in 2 days with complete resolution in 7-10 days

2. Medications