Cancer is a disease that begins in the cells of the body. Colorectal cancer is cancer that starts in the colon or the rectum. These cancers can also be referred to separately as colon cancer or rectal cancer, depending on where they start. When the body has extra cell growth it forms a growth or tumor. One of the key problems in the treatment of cancer is the early detection of the disease. Often, cancer is detected in its later stages, when it has compromised the function of one or more vital organ systems and is widespread throughout the body. Methods for the early detection of cancer are of utmost importance and are an active area of current research. Magnetic resonance imaging (MRI) established itself as the primary method for detection and staging in patients with colorectal cancer. In this paper, MRI images of colorectal cancer are used to detect the area and mean values of tumor area and distance from tumor area to other parts for staging cancer. This research paper describes algorithms for preprocessing, clustering and segmentation of MRI images. The implementation of this clustering, segmentation and preprocessing is done with Matlab 2015 (a). By using this proposed methodology the cancer is detected in its early beginning stage.