I am IBS-C, pain predominant, and I have found Heather's diet guidelines the best yet - and I have tried practically all the diets over the years! I say this to encourage you to perservere. I have followed the diet and taken Acacia since for 7 months now. I am by no means stable, but I am a lot better than I was last year. Everyone is individual, so I think it is a matter of getting the right balance of SF (soluble fibre) and IF (insoluble fibre) that works for you. This takes a lot of experimenting. Also, you need to find out which foods bother you (other than triggers). For example, I can't tolerate onions or tomatoes, but others have no problems with them.
I do fine with bean purees - probably because they are mashed up. I don't eat any raw food or salad, and I mash/puree fruits and veg and make soups and sauces. I always make sure that I eat lots of SF before I eat any IF, as this helps with preventing painful spasms. Also, I eat small portions regularly - I think this helps with C as it keeps things moving through.
I know how frustrating it can be at times - but I find that my bad times don't last as long now, and I don't get the indigestion and nausea that I did before either. HTH.