I went to an urgent care center today for a sinus infection an after the doctor checked me out he asked if I've noticed the pigment on my bottom lip, which I've had for many years. Then he ask if colon cancer runs in my family, not that I am aware of. He proceeds to tell me that pigment on the lower lip can be a sign of colon cancer!!! I have never heard this before an now I'm worried sick!!!!!! I've had this on my lip for a long time an no doctor has ever mentioned this before. What should I do??