Pseudomembranous colitis complicating ulcerative colitis.

Clostridium difficile toxin (CD toxin) causes antibiotic-associated colitis, or pseudomembranous colitis (PMC). Although CD toxin is sometimes found in the stools of patients with ulcerative colitis (UC), UC is rarely complicated by PMC. We report herein a case of PMC complicating UC, and present a review of the literature. A 71-year-old woman was diagnosed as having UC of the left colon, and treated with prednisolone and mesalazine. Later, however, lumbar spinal stenosis was also detected. After surgery for lumbar spinal stenosis, she suffered postoperative infection of the lumbar region. After 3-week treatment with antibiotics, she developed diarrhea, bloody stools, and abdominal pain. Colonoscopy revealed PMC of the cecum, ascending colon, sigmoid colon, and rectum. Stools were positive for CD toxin. As cefotiam hydrochloride, levofloxacin hydrate (LVFX), and prednisolone were suspected as the causative agents, she was treated with 1.5 g vancomycin (VCM) daily for 2 weeks without ceasing LVFX. Her symptoms improved, and colonoscopy confirmed resolution of PMC. The possibility of PMC should be considered in UC patients treated with antibiotics, immunosuppressive agents or corticosteroids who complain of gastrointestinal symptoms. These patients should be thoroughly investigated by several modalities, including colonoscopy and CD toxin testing.