I think i have either anal fissure or internal hemorrhoid, had rectal exam before no result. still pain and blood in toilet. should doc do anoscopy?

Blood in stools: It would be important to do a colonoscopy because blood on the stools could be due to colon polyps which are precancerous or internal hemorrhoid and it could also be due to colon cancer.

Yes: Go back to your doctor for a more thorough examination. Anoscopy may be one way.

Yes: You need a thorough rectal exam. Sometimes this can be very difficult to do in the office, especially if the area is very painful. It might require an exam under anesthesia in the OR. See your doctor and/or surgeon.