I have something similar, although I rarely get D anymore. I find the slow bowels annoying, and the crampy miserable "catch-up" day unpleasant, but I'm not willing to add any other meds to my already really full pill box.
At the beginning of my Crohn's journey, my GI had me take fiber (metamucil). I eventually decided that I did not need further stimulation of my already irritated colon and small bowel and I dropped it from my plan. I still eat a lot of fibrous foods: whole grain breads, fresh fruits and veggies; but on the days when I'm crampy or if I have D, I'll pull back and eat low residue for a couple of days.
If you're having D, I think it's worth a conversation with your GI to see if your meds need to be revised. I think the C is more about a nerve/peristalsis problem that is a result of Crohn's, not a direct symptom of it, but that's just a guess on my part. I really don't have any ideas on how to move my bowels any faster - even with the metamucil, all I got was a bigger bloated belly, not more frequent movement.