Here is the ral scoop. Yes always tell your doctor. BUT, to ease you. If the blood is bright red, like a fresh cut red, then it is more then likely from a hemroid, that you may or may not feel.
If it is dark in color, brown, or black, then it is old blood, which means it was new when it was in your colon, but has became old as it traveled out of your body. Then I would go to the ER, if you cannot make an appointment in the next couple of days.
so again. Dark= old, more then likely from your colon or intestines-serious
Light or bright= new blood, from the anus- not so serious
at 8:04 AM on Oct. 3, 2008