Objective To evaluate the use of preoperative MSCT in patients with clinically suspected colorectal disease after incomplete colonoscopy Methods After incomplete colonoscopy, 31 patients underwent MSCT before and after intravenous injection of iodinated contrast agent CT virtual colonography (CTVC), multiplanar reformation (MPR), shaded surface display (SSD), and Raysum images were obtained by using 4 different software in workstation The results of MSCT were compared with the findings of colonoscopy, intraoperative colon palpation, and postoperative pathology Results After incomplete colonoscopy, MSCT was successfully performed in all 31 cases Postoperative pathology revealed 22 colorectal cancers (one synchronous cancers, two with polyps) and 9 benign disease 22 colonic carcinomas were all correctly diagnosed by MSCT (including synchronous disease), 2 benign diseases were misdiagnosed as malignancy, and one polyp was missed Conclusion MSCT is a feasible and useful method for evaluating the entire colon before surgery in patients with occlusive disease