There is not any one mood stabilizer that is better for crohns/uc. Mood stabilizers are a matter of choice prescribed by your pdoc and how you respond to them. There are many choices for them to choose from and it takes time to find the right one for you and there are lots of adjustments that can be made with each one are far as dosage amounts and that is why it takes some time to find the correct one for you personally. Plus every medication works differently on each person, so it doesn't matter what I am taking, it may have a totally different affect on you. But for the sake of answering your question, I am currently taking Trileptal. I have tried many others in the past and so far this one is working well for me. I was diagnosed with B/P in August 2004.
On the other hand, steriods do have a huge affect on my moods when I need to take them for my crohns flare ups. Steriods will mess around with any one's moods, let alone being bipolar on top of it. It makes it that much harder to deal with.
I also take remicade since 1999 when it was first introduced and am currently still on it, every 8 weeks. Plus I have been taking methotrexate for a very long time. Both of these are part of my maintenance program for my crohns.
I hope this answers your question.