I am so sorry to read of all the suffering in these posts. I have had a horrible 2 years since developing IBS but I am now consistently 95% improved ! Change of diet has done the trick. I get the occasional bad day, but not so bad that it stops me doing anything. Before I was permanantly exhausted and totally losing the plot of life!
Here are the two books I used :
The Complete Low FODMAP Diet by Sue Shepherd. She is a SCIENTIST and a founder of developing the low FODMAP diet, which is scientifically shown to improve symptoms in 75% of sufferers.
Gut by Giulia Enders. This is a fun read , but again by a SCIENTIST, a medical professional. This book does not provide very specific answers but it will help you make choices and experiment to get it right FOR YOU. No two "bodies" are the same ~ there is no one size fits all answer.
But I will say, empty your cupboards of all processed food right now! Give up coffee if you drink lots of full strength. I cook very simple food from basic ingredients. Its not difficult, nor is it time consuming once you get organised. I never, ever eat out, I never ever compromise on any single meal. All my food is delicious and never boring. Hope this helps. Good luck.
I am horrified that the medical profession was absolutely hopeless at sorting this out for me. Prescribing pills seems to be all too often the route taken and it is not the answer to IBS unless there is some serious identifiable body "malfunction"................then its not IBS anyhow.