Diet definitely plays a role on how your IBS is, for a small number of people though that is not always the case. I'm an example of how changing my diet has helped my IBS symptoms... notice I said help, not completely erradicate.
There are many factors involved with IBS, not just diet or stress, etc. Fiber is still the number one suggestion given by docs and researchers as to helping IBS patients. Not all will agree with that though. I take fiber and eat more fiber and my symptoms have improved. I also make sure to drink plenty of water and stay away from things that I know will cause problems.
Certain foods can be identified once you start keeping a food diary. Write down what you eat and what your symptoms are for that day/time. You soon start to see a pattern and you can start identifying trigger foods, ingredients, etc. Everyone is different in terms of what kind of foods cause the most problems so an global IBS diet is out of the question. You just have to identify what causes you problems.
Given that you have IBD as well, it may be a little harder for you because your triggers for IBS vs your triggers for UC could be totally different.
Good luck and take care
Co-Moderator ~ IBS Forum
Co-Moderator ~ Lupus Forum
Dx: IBS 1989, Diverticulosis 2004, Idiopathic Acute Colitis 2006, UCTD 2007
Meds: Plaquenil 400mg, Chlorzoxazone 500mg, Lyrica 50mg, Protonix 40mg, Naproxen 1000mg, Klonopin PRN, Miralax 17g, Supplements