If a screening test reveals suspicious results, then a colon biopsy is done. A colon biopsy can be conveniently done during a colonoscopy or can also be done surgically. During a colon biopsy, small amounts of colon tissue are removed and then sent to a pathology lab to screen for evidence of cancer. If cancer is present, then the stage of colon cancer is then determined through colon cancer surgery to remove the cancer. Surrounding lymph nodes are tested and may also be removed during the surgery.
source : cancer.about.com
source : cancer.about.com
