I've never had trouble with pickles, but then I'm C...and I don't have any during my D episodes. Maybe you could try a couple of slices on a turkey sandwich and see how you fare? If your belly doesn't object to that, then perhaps a spear after you've had some soluble fiber might also be ok.
We get yummy garlic dills from a vendor at our local farmer's market, so I know that they're fresh and that there's no preservatives. Since IBS'ers are extra sensitive to additives and the like, you might want to go with something like that. Do you have any neighbors with cucumber plants who like to pickle?