Much of the info for IBS is about D since that seems to be more predominent than C. Those that I know personnaly who have IBS are D and I'm the odd one out with C. There are however, plenty of Cs around as I found out when I got on this website. I do use Miralax and have for a number of years now. It is non-addictive. I use the prescription version but they do have it as an OTC. I don't know if there is any difference between the two(strength, fillers and all). I've been able to use 1/2 a dose every other day and I use the acacia fiber too. Magnesium tablets do help out too. Just keep trying different things till you find what works for you.
I follow the diet with a twist since wheat is an issue for me. You don't have to eat bland at all. I cook for my family and it's not bland in any way. We love garlic and spices but I'm careful with the cayenne pepper since that will irritate me way too much. I like Zesty Blend mixes or the Tones mixes from Sam's.
I get the nausea sometime when I get a bad reaction. The body wants to get rid of what is bothering it, plain and simple. When I get an attack I do several things. I take a pamprin(I found by accident that it helps with the cramps immensly and my doc says use it if it works), then I drink a cup of hot peppermint tea mixed with Acacia and 1/2 dose of Miralax with a peppermint tablet. Next I heat a hot pack and then lay down with it on my gut(to ease the transverse colon cramps) and moving it to my back(where the descending colon is closer). This calms things down greatly. While the initial stool tends to be hard it gets pushed out by the softer stuff behind it inside a relaxed colon.
Just keep on trying. You'll find your own personal way of eating that will help you. I still react at times and can't figure out why but I do ok more and more often now a days.
-------------------- Catnut IBS-C for many years, finally diagnosed in 2005. Wheat and dairy sensative.