22 year old male terrified of colon cancer my appetite hasnt really been there lately how likely is it due to colon cancer what are my realistic odds?

Very unlikely: Great majority of cases after age 50. Earlier cases usually have a strong family history of colon cancer, or familial polyp syndrome_ fairly rare. Bad appetite can be due to lots of causes in a 22 year old. Colon cancer is a very unlikely cause.

Odds are small....: Colon cancer would be quite rare at your age. Are you having symptoms such as bleeding from the rectum (not usually cancer - more likely to be a tear or hemorrhoid) or black bowel movements? Do you have a family history with many folks who have colon cancer at young ages? Have you been advised by a doctor to start having colonoscopies early? If not, you may want to talk to your doctor re: anxiety.