A friend of mine spent 5 days in the hospital. She is in her early 70s and looks less than 60! She felt and looked in good health.
She never told anyone she was bleeding from the rectum for almost a month and did not go to the doctor. One morning last week a friend observed walking in our bldg's 9th fl hallway - and she almost collapsed... The friend took her to a hospital emergency where she was admitted.
The tests revealed she had NO cancer. Neither did she have ANY pain!! However, she had 'bleeding polyps'...some could be removed and some had to be cauterized. One had to be clamped off with absorbable stitches. None of this is too common, but it DOES occur.
I share this with you because -- "just because" you have bleeding not due to fissures or hemmorhoids -- do not assume that is 'must be cancer.' However, the amount of blood she lost should have motivated her to get herself to the doctor PRONTO. But it didn't. She will have to be monitored closely for awhile.
No specific diagnosis could be named. This is just to add to your information, in case you might have similar problems. See your doctor sooner rather than later!