I have an "attack" of lower abdomen cramps & constipation that lasts a few days once every year for 3 & half years. I've had blood in stool in the past not sure if its connected. My primary doc does not think I have colon cancer. Worried. Can it be?

Health phobia. Please continue to see your family doctor. We can all get ill but the probably of it is very low. See a book called Feeling Good by David Burns for some self-help cognitive therapy to change your self talk. Peace and good health.