Histologic Findings and Clinical Characteristics in Acutely Symptomatic Ulcerative Colitis Patients With Superimposed Clostridium difficile Infection

Objectives To examine biopsy specimens for histologic features suggestive of Clostridium difficile infection in patients with ulcerative colitis (UC). Methods Nine patients with UC had colonic biopsy specimens taken during a symptomatic flare that coincided with positive C difficile ( C difficile +) tests. Twenty-eight controls were biopsied during a UC flare but tested negative for C difficile . We reviewed the slides for evidence of pseudomembranes, ischemic-like changes, degree of colitis, and lamina propria hemorrhage. Results In C difficile + patients, 4 (44.4%) of 9 had microscopic pseudomembranes compared with 11% in controls ( P < .05). Other histologic/clinical features were not predictive. Conclusions Although the presence of microscopic pseudomembranes suggests C difficile infection in patients with UC, sensitivity and specificity are poor; biopsy findings do not reliably detect this infection in patients with UC.