I don't know about the BIG D because during a flare up I go the other way :S BUT do you know if you have fistulas? The really hurt and when I muscle contracts part kind of reminds me of when I discovered my perianal fistulas....
As for the eating...During a flare up I eat things like...
Pan fried haddock, steamed veggies with butter or cheese sauce (lubricant), adding extra gravy, butter or sour cream to foods (yes its fattening but it helps things through.), boosts/ensures, bananas, mashed potatoes, frozen yogurt, soft mushy things that you can get your nutrients out of ... stews, soups, chowders, those sorts of things...while they may be high in fat in some instances, i lose so much weight from not wanting to eat during a flare up that it equals out usually...I know that probably isnt a great help...depending what meds you are on making sure you get your calcium and vitamin d, magnesium, etc....
INCREASE YOUR FLUID INTAKE!!! REALLY!!!! I know you have the BIG D problem...but all that fluid you are losing....you need to keep hydrated or they won't even be able to find a vein to give you your infusion.
Hope you can find some soft stuff to eat.....drop me a line anytime.