What are some signs or symptoms of colon cancer?

Possible signs and symptoms of colon cancer include a change in your bowel habits to include constipation, diarrhea, or a change in the caliber of your stools for more than a couple of weeks; any rectal bleeding or blood in your stool—don’t assume the bleeding is from hemorrhoids; unexplained weight loss, fatigue or anemia; and feeling that your bowels are not emptying completely.