Dont start stressing too much on the colon cancer issue until you have had a
colonoscopy and a diagnosis from your doc. I will say that you 100% should have the
colonoscopy, especially if you have immediate family with colon cancer. If the colon cancer is distant, like great uncles, 2nd cousins,etc, your chances of having it are less likely. Keep us updated, but remember there are tons of other issues it could be.
As for the raised alt, I had the same.