3. Broken Skin
Piles demonstrates how very red blood might be the result of damage near the outside of the digestive system rather than deep inside (which causes a much darker discoloration). Broken skin can cause the precise same thing. If you have a small cut, split skin, or even some kind of rash or irritation, then this can likewise cause the appearance of bright red blood that may make its way into the stool.
Of course, you are more likely to notice this when wiping and you may also notice that it is sore to touch. If this is the case then you should find that it heals and goes away on its own after a short time.