I think if I ate a nut I'd have to be rushed to the hospital! Nuts are probably in the top five of no-no's for IBS sufferers. Avoid them at all costs.
I've recently started eating barley again after many years. It's probably one of the most nutritious foods in nature. It has three times the fiber of brown rice, a great blend of soluble and insoluble. I cook it like risotto or pilaf, with veggies and chicken broth, but you could use veggie broth instead. It really has helped get things moving without the bloating and gas I sometimes experience with brown rice.