Hi! Well, I have Crohn's disease and had been misdiagnosed with ulcerative colitis so I do know about cramping. For me, I had to stay away from fresh fruits and veggies...no salad. I could eat canned, though. I also had to stay away from spicy things. It was a pretty bland diet but it made me feel better.
Another thought is you could possibly have food allergies like lactose. I had a friend that suffered with IBS symptoms for years and then discovered that she was lactose intolerant! She started using the special milk (Lactaid, I think) and avoided dairy and her symptoms cleared up. This is something you could try. Some people are allergic to gluten, too.
I do hope you have talked to your doctor about this. IBS symptoms can be very much like other problems so you want to be checked out by your doctor.
I hope this helps you some and I hope you start to feel better soon.
Sherrine