believe me, i know EXACTLY what you are talking about. it has caused me tremendous amounts of anxiety!! and i'm going through one of the bad weeks, and the past 2 days i've had absolutely no appetitite because my stomachs been in knots.
I would try that diet for a week, just to give your digestive system and intestines a break, as it is very bland, and does a good job of slowing things down.
the brown rice is what you want to go with. as far as the applesauce, go for the natural/unsweetened kind.
there are a lot of different anti-spasmodics out there. i've heard of some people that try one name brand, have no luck... go to the next, and get relief.
have you tried Librax? its a combination of an anti-spasmodic and anti-anxiety drug(benzo). thats supposed to be one of the better options for IBS as far as anti-spasm. go.
i've seen on you post before, and can't remember if you've been on xanax before, have you?
have you tried the calcium supplements, like caltrate? it's not an instantaneous change, but if you are religiously taking it every night, some say it will start to work within 2-4 weeks. and i've visited a lot of different IBS boards, and a lot of people say it's helped with the urgency that accompanies the diarrhea. some have even gone off their 12 per/day imodium routine after being on calcium for awhile.
i really wish you well, and will say a prayer for you

we seem to be suffering similarly right now.
any more questions ask away!