Pseudomembranous Colitis (Clostridium Difficile)

R. Brooke Jeffrey, MD

Key Facts

Terminology

Synonyms: Antibiotic colitis, Clostridium difficile (C. difficile) colitis
Acute inflammation of colon caused by toxins produced by C. difficile bacteria

Imaging

Best diagnostic clue: Marked submucosal edema over long segment of colon
Location
- Usually entire colon (pancolitis)
- Rectum, sigmoid colon (80-90% of cases)
Thumbprinting
- Unusual, wide, transverse bands due to haustral fold thickening
CECT
- “Accordion” sign: Trapped enteric contrast between thickened colonic haustral folds
- “Target” sign
- Pericolonic stranding
Best imaging tool: CECT with oral contrast
Protocol advice: 150 mL IV contrast at 2.5 mL/sec with 5 mm collimation, 5 mm reconstruction interval

Clinical Issues

Elderly at higher risk for developing PMC and recurrent PMC
Clinical profile: Patient with history of watery diarrhea after antibiotic use or hospitalization

Diagnostic Checklist

Check history of antibiotic use or debilitating diseases
Suspect in any hospitalized patient with acute colitis

(Left) Graphic demonstrates pancolitis with marked mural thickening and multiple, elevated, yellow-white plaques (or pseudomembranes). (Right) Axial CECT in a 62-year-old man who presented with diarrhea and dehydration demonstrates a classic case of pseudomembranous colitis. Note the severe bowel wall thickening throughout the entire colon

. Pseudomembranous colitis typically presents as a pancolitis, as in this example.

(Left) Axial CECT in a 47-year-old man who had been taking antibiotics for 2 weeks for sinusitis, now presents with a 2-day history of RLQ pain, fever, and concern for appendicitis. Note the marked submucosal edema of the right colon