I have the same problem, last couple of months blood in my stools. This has been a recurring problem, maybe once or twice a year for last two years. I've been to the doctor a few times as I was concerned about it. She confirmed that I had hemorrhoids. She said she would be more concerned if
1. there was a history of bowel cancer in my family
2. if I found blood in my underpants, i.e. not as a result of passing stools
3.if the stools were a more dark red instead of bright red (indicating that the problem was further up the colon)
Saying that she is willing to send me in to hospital for a better look if it was worrying me,
With her, the bottom line is that blood on its own is not a concern as in the vast majority of cases its down to hemorrhoids, but if the worry is getting in under your skin then the best thing is to have it looked at in order to rule out anything sinister, so as to have peace of mind.
Hope this helps.