A disabled child before 22 gets the "adult" version (older than 18) of disability, which means you were deemed disabled by the adult standards, not the child standards which are different. While going to school full time and being successful could indicate you were no longer disabled (depending on what factors you were deemed disabled by and I would think your college experiences being asked to leave would be part of that), "trying the waters" so-to-speak by taking an online course or two would not bother them.

Some illnesses do not engender their looking into as often as the prognosis is not one where the person is likely to become well quickly and they already have in place where you report any changes such as schooling or jobs, income, getting married, etc.