If your doctor thinks an area of the bowel needs to be evaluated in greater detail, a forceps instrument is passed through the colonoscope to obtain a biopsy. This specimen is submitted to the pathology laboratory for analysis. Biopsies are taken for many reasons, and not necessarily because cancer is suspected. If the colonoscopy is being performed to identify sites of bleeding, the areas of bleeding may be controlled through the colonoscope by injecting certain medications or by sealing off bleeding vessels with heat treatment. If polyps are found, they are generally removed if safe. Generally, these procedures are not painful.