My GI says that sodas are terrible for your stomach in general, especially if you have crohns. I usually drink water or cranberry juice, but if I go out to eat I always get a soda to "treat" myself. I do notice a difference since I dont drink them that much tho, I used to drink like 3-5 a day, now maybe 1-2 a week, now when I drink sodas I get a sour stomach.