RADIOLOGY: GASTROINTESTINAL: GI: Case# 94: C. DIFFICILE COLITIS. 51 year old female with recent history of cholangitis currently on antibiotics. There is marked thickening of the wall of the entire colon, less pronounced in the rectosigmoid region. "Thumbprinting" or mucosal fold thickening is well-displayed here. Clostridium difficile colitis, also known as Pseudomembranous colitis, often occurs in the setting of recent antibiotic administration. CT findings include thickening of the bowel wall and haustral folds. The haustral fold thickening results in the classic thumbprinting pattern depicted above.