Hi itswhit. I'm so glad I saw your post because you sound just like me!!!!!!!!! I was diagnosed with Crohn's in the early 1980's and my flares have always been exactly as you describe; however, I have only been admitted into the hospital once in all these years, and that was for a blockage. There have been many trips to the ER though where they administer fluids and give me Zofran to stop the nausea. When I have flares, they usually hit during the middle of the night. I get dizzy, feel faint, break out in a cold sweat, go at both ends, have chills, etc... I can feel fine when I go to bed but then WHAM - I'm sick as a dog just a few hours later.
Anyway, over the last year or so, I have started putting two-and-two together and now realize there are usually signs that I'm about to have a flare. For example, I got sick as recently as last week and missed two days of work. While I was at home recouperating, it dawned on me that I had been feeling dizzy for the past two weeks, my hips and back had been hurting, and my tummy hadn't felt just right. They were all vague symptoms, but I know now they were signaling an impending flare. Oh, and this was something new for me... my left index finger and my left big toe both swelled up, turned red and were very painful just a day or two before the flare. I've heard of that happening to Crohn's patients, but it was the first time it had ever happened to me.
I hope this helped. I love hearing others' Crohn's stories because it makes me realize it's not all in my head. Happy Holidays!