Advice about Bright Red Blood in Stool

I am 17 years old, relatively active, and more often than not I am strictly eating vegetables. Starting this week, I noticed bright red blood in my stool. Not a whole lot, but just in one part of the poop. The minute I noticed it, I became very concerned that it could be colon cancer. But, I realize that this is one possibility among some others.
Source: About.com Colon Cancer - Category: Cancer & Oncology Authors: Tags: health Source Type: news