Hard to say, but for a few years I was getting it 2-3 times a year. It was AWFUL, and I always ended up in the ER getting fluids and anti-vomitting meds. They would also run a ct-scan, because I too never knew if it was Crohn's or a bug. I honestly still really don't know. But I think it may have been stomach bugs, my son's old public school had it going around constantly it seemed. Now that we homeschool, no more stomach bugs! *knocking on wood* that I don't get it again like that this year, it was just awful.
Hope you can figure out what's causing yours, and that it stays away!
Diagnosed with Crohn's Disease 2/06 after sever GI bleed. Has been suffering since 1998. History of rectal fistula and gallbladder removal. Just finished tapering off Prednisone *YEAH*, Asacol, Questran, Toprol XL (for high blood pressure).