I have blood in my stools sometimes, does that mean i have colon cancer?

It depends: Rectal bleeding can be caused from hemorrhoids(commonest cause) or by colon cancer. So an examination is required to find the exact cause. Any rectal bleeding is a signal to go to your doctor for a complete examination to find the cause and treat it accordingly.

No, that is just one: Possiblity. Most likely is hemorroids, then infections, inflammatory bowel disease, diverticulosis, angiodysplasia. But you are right, the most deadly is cancer, so have it checked out.

Possible : All rectal bleeding must be evaluated, and one of the reasons that is so important is to rule out cancer as a cause.