Two things seem to trigger my symptoms: stress & fatty foods. I dealt with the stress by changing jobs last year, and I now have to completely avoid rich, fatty foods: bacon, mayonnaise, most kinds of cheese, ranch dressing, anything deep fried; because they all cause horrible stomach pain that lasts anywhere between 1-3 days. So, I base all my meals around a lot of carbs: bagels, pasta, rice, bread, tortillas, potatoes. Veggies are no problem for me, nor is spicy food. I try to eat small servings of chicken, turkey, pork or seafood (for protien) at least once a day. I also try to keeping meals small, so I don't feel bloated right after eating. I NEVER drink sodas, diet or otherwise; soda pop is very, very bad for ones stomach - it makes me feel very, horibly bloated and cramped-up! I started taking Citrucel fiber tablets EVERY DAY, about 18 months ago at the suggestion of a physician, and have had only two severe symptomatic bouts since then. And, of course, exercise helps tremendously - it relieves stress, and also burns off all those carbs!
Remember, everyone's symptoms are different with IBS - you just need to find your specific "triggers", and reduce or eliminate them. I sincerely wish you Good Luck!!!!
~~~~~TrekChick