Role of Clostridium difficile in a case of nonantibiotic-associated pseudomembranous colitis.

A 57-yr-old woman with chronic diarrhea, mild azotemia, and red cell casts in her urine was found to have pseudomembranous colitis. She had not received antimicrobial agents for at least 2 yr. Membranoproliferative glomerulonephritis was found in kidney biopsy, and her renal function improved spontaneously. Pseudomembranous colitis was diagnosed by endoscopic biopsy. Her stool contained a cytophatic toxin that was neutralized by Clostridium sordellii antitoxin, and Clostridium difficile was cultured on selective media. This case indicates that C. difficile may be a cause of nonantibiotic-associated pseudomembranous colitis, as well as antibiotic-associated pseudomembranous colitis.