Hi there...I've actually been having the same problem myself. The only thing that's keeping me from going to the docor is my lack of insurance (I just graduated college, new job with no insurance until after 3 months). Is it possible that there is some sort of tear? If you do go to the doctor let me know what he/she says...I'd be curious since I plan on going myself.
PLEASE GO SEE A DR. asap!!!!!!
You definitely need to go see your doctor. Do you have any problems with spicy food? Do you have diarrhea at any time? You need to see a dr. asap to rule out anything that could be happening.
If it's fresh blood then the it's highly likely you may have a problem with your rectum. Sometimes if your stool is very stiff/hard this type of problem could occur...but I would go see your doctor.