Virtual Colonoscopy

I had a virtual colonoscopy and cbc, all came back normal. I am 42 no familiy history CC or IBD.
Could my diarrhea be because IBD? No blood ever, dr. says most probable IBS but can only be sure after a traditional colonoscopy ( dont want to take it). Diarrhea almost always one go in the moorrning when I have an important work related activity, ( once every week or two) naver woke up at night because of it, although i have had gases that wake me up at night and sometimes after a meal a would get a serious gas attack sometimes with diarrhea other  pellet stools others nothing more than gases..... is a virtual colonoscopy good for discarding serious IBD, I have read that even a Barium could help?