Pseudomembranous Colitis

Pseudomembranous Colitis is caused by overgrowth of Clostridium difficile and is characterized by a pseudomembrane of necrotic debris in the colon, diarrhea, foul stools, abdominal cramps, nausea and vomiting. Antibiotic use, intestinal ischemia, obstruction, irradiation, shock, and long-term steroids may trigger this disease. Diagnosis is made by detection of C. difficile toxin in a stool sample and treatment is with Metronidazole or Vancomycin. Plain films will show a dilated colon, ascites, and a nodular thickening of the haustra. Barium studies will demonstrate an irregular lumen, thumbprint indentations, and superficial ulcers. CT will reveal wall thickening (~15cm) with a target-like appearance, pericolic fat inflammation, ascites, and the "accordion sign" with stripes of intraluminal contrast trapped between the nodular, hypertrophied wall.