Patsy Catsos has a good book IBS Free at Last, it is an excellent book for reference-with the elimination diet. I refer to that whenever I have question. My gastro has told me I am gluten intolerant and 100% agree, can't eat any without getting sick, sometimes taking a couple weeks till I am over it. Definitely gluten-free is suggested with this diet and lactose-free products, so those two are a given to start. Then, even things like ketchup is a no-no.
Talk to your doctor about the permanency of this diet. I, on the other hand have no doubt as this is a chronic condition. I have recently given up brewed coffee, now that was a tough one. I should not have been drinking it at all, it creates stomach acidity but being the stubborn person I am I still drank a couple cups of the 50%. Till recently. People don't understand but if you have this problem this diet is worth the sacrifice in order to feel better. I cannot "cheat" but sometimes willing to take small risks as you describe. Make sure you stay away from any artificial sweeteners too! I think it is better to understand the foods you can eat as opposed to forbidden foods.
There are LOW FODMAP recipes on Pinterest, have you looked there? Might help eliminate boredom. Yes, there are some foods that are approved on one version of this diet and it may not be listed on another. You can always try it. My biggest problem is sometimes I can eat something one day and have no problem but the next time, not so much. I miss a lot of favorite foods--pastas, pizza, ice-cream, hoagies, fresh bread,-it's not that I ate a lot of these things but once in a while was a real treat. Nutritious foods like broccoli, cauliflower, beans, lentils, rye bread, apples, pears, peaches all no-nos.
Question, did you lose a lot of weight before going on this diet? (Without trying) A couple of my doctors I think, did not believe I was eating normally. There are doctors unwilling to accept this type of diet--actually, they recommend high fiber. Tried that OMG. Then they look at me like I was crazy. My local Drs just weren't current. Have to travel a ways to a gastro but it has proven to be worthwhile. He is willing to try things even if it's not been completely accepted by mainstream. Peace..