It took me over a year to stabilize, so I wouldn't say it's unusual, but even so. I think at this point you should start looking at non-diet triggers (and solutions). I know that, personally, I'd be a complete wreck IBS-wise without my antidepressants... they're just as important to my stability, if not even a little more important, than the diet itself. If you have any kind of stress or anxiety, especially, this might be something to consider.
Also, why are you taking glutamine? And I know spirulina is one of those generally beneficial things, but could that be bothering you? I'd try cutting those 2 things out, unless you've tried that already.