I got a colonoscopy 6 days ago and i have recently started masturbating. is that bad? or is it fine?

Depends on why: It's fine to do a colonoscopy, if needed. Whether it's bad or not bad depends on why a colonoscopy was needed, and what was found or not found on the procedure. It's also fine to masturbate, as long as one is doing it in moderation (too much of a good thing can become bad). If the doctor advised to wait a certain number of days before engaging in sex activities, one should follow the instructions.