Welcome to the IBS Forum!
I'm sorry to hear it took so long for your IBS diagnosis. However, be happy it is "only IBS" --- Crohn's is no picnic.
Anyway, what Des says is correct... Calcium may help you with D. Here is a great link: Calcium Info
If you're having a lot of bloating as well you may want to try Beano or Gas-X. Also try staying away from gassy foods like cabbage, lettuce, peppers, onions, beans and cauliflower. There are plenty more, but those are what I remember off the top of my head.
Caffeine and alcohol are also big triggers for most of us IBSers.