S.,
I was diagnosed with IBS back in March. My doctor gave me Symax if the cramping got really bad but not something to take on a daily basis. His advice was to increase my fiber intake to 25 grams per day. You can do that with diet alone, but it can be difficult. He recommended a high fiber cereal in the morning (Fiber One is the highest in fiber) and using a Fiber supplement a couple of times a day (Benefiber or FiberSure). The supplements dissolve completely in water and have no taste. If you are getting nowhere near 25 grams of fiber per day right now, be sure to gradually increase the amount of fiber over a two or three week period. Otherwise, you may feel even worse. Anyway, I am doing so much better now. I had a lapse when I got pregnant because I had no appetite whatsoever in the first trimester. I had a tough time getting the fiber I needed. I am now 23 weeks along in my pregnancy, and I recently went back to my GI doctor. Again, he hammered into me the importance of consistently getting the fiber. I have started back up with the fiber regimen, and it has made a huge difference. Another thing that may help is to take a probiotic supplement for a couple of weeks or eat Activia yogurt on a daily basis.
Did your doctor mention anything about having a colonoscopy to rule out anything more serious?
Good luck. I know how miserable it can me.