Hi....I think I have something very similar. It starts with rectal pain (not always with a bowel movement). The pain is so severe I am sometimes in tears. It then progresses into a cold sweat, nausea, vomiting, lightheadedness and extreme weakness. I end up on the bathroom floor fighting between the urge to get back on the potty or sick my head in it. Te pain has progressed to this level about 6-7 time over the last 2 years. Many times I feel the pain and take a muscle relaxer my doctor gave me (hyoscyamine) that seems to keep the pain at bay (though not always). I had a sigmeudal colonoscopy (scan was clear) just today and after hte procedure when I was passing all the air he used, I had another "epidsode"...sweating, vomiting, wekness, etc. Nothing more embarassing than laying on the doctor's bathroom floor.
The next step for me is a trip to my OB-GYN t make sure everything is in order internally. Then we may have to move external to retum and do a cat scan or MRI. I have not been able to find much on these symptoms on the web until I read your post.
Have you had any luck with a diagnosis?
IBS, in my opinion, is a cop-out diagnosis. The way IBS is supposed to be arrived at is after you've had the million dollar, cadillac workup to rule out everything else the docs can think of. If you see a doctor and he tells you it's IBS without doing any testing, colonoscopy, CT scan, labs, etc., he's nothing more than a lazy doctor.
When did you last see a doctor for this problem? What testing have you had recently? Have you tried to keep a food diary to help you determine if some foods make it better or worse? That information could certainly help your doc reach a diagnosis. As for corn, that's just not a veggie that is easily digested, and it's not uncommon to "see" it the next day. :-) Try to eat like good old mom (or grandma) said - apple a day, plenty of leafy greens, and all that. Stay away from fast food and keep alcohol to a minimum.