Hi Trish! I'm a Trish too! Welcome to the boards!
Probiotics are friendly bacteria which sometime help repopulate the gut with the good flora and eliminate the bad, which often causes gas and bloating. Since you suffer primarily with D, they will likely be beneficial for you. You can find them in the refrigerated section of your local health food store. Another alternative might be calcium supplements. I have seen many members here recommend this as a way to slow down the D.
Foods that might help: bananas, whole wheat pastas, brown rice, white rice, yogurt, high fiber cereals. You will probably have to experiment to see what helps. IMO, it's always best to get your fiber from food rather than the OTC supplements. You will probably have to try many different options to find what helps without adding to the bloating and gas.
Does you bloating decrease after you've had bm's or passed gas? I find that to be the case for me although my problem is C, not D. If passing gas helps, you might want to try a heating pad, some gentle belly massage, and lying on your left side after meals. I have found all these things almost as helpful as the meds I've used over the years.
Good luck and keep us posted!