How do you know if you have a family history of colon cancer if all the old folks get colonoscopies, get polyps removed, and say nothing about it?

Ask: Go to your older relatives & ask them- not just about colonoscopies, but about their parents/grandparents, who had what & who died from what. You'll get valuable family history on a number of topics. Only about 5% of colon cancers occur in families with a history of colon cancer, so screening is more important than family history for this.

Great question: If your family won't tell you their history, then there is no way to know your family history. Keep asking and explain the importance.

Not all family equal: The family history one is most concerned about is first degree relatives less than 60 with an advanced adenoma (large polyp) or cancer. They same applies for 2 second degree relatives. Even if you grandfather had cancer at age 70 it doesn't change the screening recommendations for yourself.