It depends on what disease you have and the reasons for getting them done. My friend has a jpouch and UC, had colon cancer at 17 and hasn't had a check up in 10 years. I guess nobody told her to get looked at again, but she claims her doctors sucked and at that age nobody really talked to her like an adult.
I have to get scoped every 3 months as of right now but I have FAP.