IBS is a symptom of something else, you have an irritable bowel from something.
I think if you really buckle down you will start to feel better. You need to not use the same condiments that have had a gluten knife in them- peanut butter, jelly, mustard, mayo, butter, etc. You will need a new toaster-because of gluten crumbs- and if your non-stick pans are scratched you will need your own new pans for gluten-free only, any wooden kitchen ware that has had gluten containing foods on it is contaiminated (CC) and can make you sick, scratched plastic needs to be replaced also. If your SO eats gluten you can get CC from kissing them before they have brushed their teeth. There are some people here that 'just a crumb' will make them very sick.
I hope you are able to get some answers so you can get better.