Hi, I just wanted to WELCOME you as well.
I'm going to go out on a limb and say that yes, it might be a possibility that the colon cleansing put you over the edge. As dbab mentioned, it is a controversial topic on this site, however it has been said by a number of doctors that they should not be done. I'm not saying you were wrong to do it, just that is it is a questionable procedure. The argument against doing the cleanse is that it is not natural and infact does strip away your body's natural flora (like you mentioned). We need a balance of good bacteria and bad bacteria to have proper digestion - those of us with IBS can't seem to find that happy medium.
Like Keri mentioned, probiotics are GREAT to take. See if you can find one that agrees with you and take it regularly. You will see a difference after about