The frequency of your colonoscopies is something your physician should decide.
Patients I have taken care of with colon polyps were usually over the age of 40. Polyps can be hereditary.
Depending on what kind of polyps you have will determine if you are more susceptible to colon cancer.
Please go to pubmed (a medical research article search site) and search for colon polyps in the young
You will find a paper in the Scandinavian journal of gastroenterology
that came online 10/24/18
im 17, an i just found out i have hemriods and colon polyps, am i at risk of cancer?
I was diagnosed with Hyperplastic Polyps Syndrome at 27. In the year following I had over 100 polyps removed. I was told by my specialist that this is extremely uncommon as they don't normally see people in our age bracket for colonoscopies. I would be really proactive and have colonoscopies regularly(6-12 monthly) until you have one come up with no polyps found. They are not so bad when you consider the alternatives! Goodluck to you.