From what I understand, only certain types of antidpepressants work on the bowels. The one I've seen mentioned on here (of course I can't remember what it is...) is a fairly recent addition (been out a year or two now). I haven't heard that the older types work on the bowels any. So, yes, it could be that this one will work where others have failed in the past. Also, antispasmodics seem to be notorious for working or not working (nothing in between); it can take some time to figure out which one of those will work on you as well. Of course, if your problems stem from, say, a bleeding ulceration of the intestines, no antispasmodic will work, because it's not a spasm causing your pain and other problems. For that matter, antidepressants won't work if your bowel problem isn't caused by functionality/motility problems; they won't do anything to help ulcerations either.
Have you checked into the UC and Crohn's boards yet to see if they have any recommendations for things you can do to maybe help yourself?