Loc: Northern California
Per Heather's book, a colonoscopy is a must for diagnosing IBS properly. X-rays and barium enema (outdated) are not reliable for IBS.
In addition, you need to drink LOTS of water or tea every day. Minnie says we need more than 8 glasses of water or tea per day.
I suggest that you step up your water/tea intake, and make arrangements for a colonoscopy. The procedure is not uncomfortable at all, and the prep the night before will clean you out good, and then you can start fresh again.