Dark-lumen MR colonography combining a water enema with intravenous contrast administration is a rapidly evolving, minimally invasive method of evaluating the entire colon (1-2). Results of several preliminary series indicate that this technique has a high sensitivity for detection of colorectal cancer and significant polyp lesions as well as inflammatory disease of the bowel (3). Since bowel movements are depressed during the examination a digital subtraction technique comparable to vascular studies might be applicable and facilitate detection of regions with increased contrast uptake