I keep having blood on my stool but no pain. my dr check and said nothing to worry about said no external piles. but thats all he would do. could it be cancer? im in my 30s! its very worrisome!! rarely i have an itch but still no pain?

For peace of mind have an office anorectal examination by a proctologist,colorectal surgeon or gastroenterologist. If no associated bowel problems trivial amounts of bright red blood could be caused by internal hemorrhoids ,anal fissure or some perianal dermatitis.

No amount of blood on stool is normal!!! See a colorectal surgeon and give a thorough family history of medical problems to get a proper evaluation and treatment plan. Do not ignore and consider finding a more qualified primary doctor. It could just be a fissure or internal hemorrhoid but it should not be ignored.