I've just recently been tentatively diagnosed with IBS. For the past few years, once or twice a year, I have had episodes where all of a sudden I get cramps that quickly become severe (worse than any pain I've ever felt including four natural childbirths). I almost immediately start feeling dizzy, light-headed, like I'm going to pass out. I also break out in a full sweat and feel nauseous. Fortunately, up until this last episode I've been at home and able to get to the bathroom immediately. Once there I put my head down between my knees and the light-headedness eases. Then I'll have a normal BM, but then over the course of 10-15 minutes the BM becomes increasingly loose. After 15-20 minutes all symptoms pass and I feel OK. However since June I have had four episodes, with three just in the last five weeks. The last one occured when I was at a baseball game. The only restroom facility was one port-a-john. When the cramps and light-headedness started I didn't want to tie up the sole restroom for 15-20 minutes so I tried to fight it. I laid my head back against my chair and next thing I knew my husband was lifting my sunglasses off my eyes and asking if I was still with him. I had passed out for approximately 30 seconds. Scared him half to death. When I came to I still felt crampy so went to the restroom and had normal BM. A few minutes later I again felt cramps and returned to restroom and had loose BM. After that I was OK, just felt a bit drained and tired. Has anyone else had these symptoms? The gastroenterologist prescribed hyoscyamine and I'm scheduled for a colonoscopy this Friday. I would greatly appreciate any feedback.