You shouldn't have any significant pain after a colonoscopy. Sometimes because of the air that is used to insufflate and dilate the colon during the procedure, patients could have some mild cramping. If procedures are conducted during the colonoscopy, such as a polypectomy or a biopsy, then you may have some very minimal bleeding after the procedure. If you are on any blood thinners and any instrumentation is done, your risk of bleeding is slightly higher. But if you do have any significant bleeding, more than a few drops after a colonoscopy, you should definitely contact your doctor.