Timing of colonoscopies

So, I had non specific colitis (positive prometheus test for crohn's though) and had to have 10" of my sigmoid and descending colon removed a little over a year ago. Three weeks ago when I had this bad bug that was going around, at the end of having diarrhea, I had mucus and blood. After that things went back to normal, or so it seems. So they want to scope me but couldn't get me in until the end of the month. If all is well, my question is why get it? Shouldn't I wait until it happens again? I have a little bit of pain and I guess I should get one for prevention sake but don't want to if I don't need it. It just seems that before my scopes didn't come back positive unless I was really sick at the time.