TLDR: I would recommend this book, to expand your recipe repertoire (especially for the price) but you can't follow the recommended meal plan to the letter if you're a beginner so it's not what I thought it was and what I needed.
The short version is that it has a lot of good info about IBS, FODMAPs and the overall diet and "challenging" process, but my issue is with some of the recipes in the meal plan, which is the main reason why I got this book. I needed some guidance because everything I know how to cook has FODMAP ingredients in it, and I didn't want to have to hunt for recipes and put together a meal plan that worked.
The book recommends using the Monash University app to help figure out what is acceptable to eat, because they are the pioneers of the FODMAP diet. However, the book doesn't follow its own advice during the preliminary stages of starting the FODMAP diet, before the "challenge" stage. Theoretically, you're supposed to start with ONLY stuff that is definitely low FODMAP, so that you can cleanse your system out. THEN 3-4 weeks later, you challenge to see what your unique tolerance is for each of the FODMAPs. The problem is that there are several recipes in the book's week 1 starting meal plan that ask you to make something that has ingredients which (according to the Monash app) are only "green" if you have a small amount (cabbage, or unripe bananas), are borderline "yellow" (zucchini) or are actually "red" in the app (blueberries). This makes it really hard to follow the diet if you're a beginner and don't know what your sensitivities are yet and these recipes terrible choices for the beginning stages of the diet, when you're trying to figure it all out. Maybe the author can eat small amounts of blueberries, and cabbage and all that, but not everyone can, so having these in your first week of trying the diet defeats the purpose.
Also, a side note, they have ridiculous amounts of food to buy in the first week and it's really expensive obscure stuff. If you're cooking for one, you will end up with tons of food (especially fresh produce that you can't freeze) that you won't be able to eat before it starts to spoil. Then there are tons of leftovers, and you end up eating the same thing for 3 meals. This is exactly what I was trying to avoid because as you may know, high quantities of the same low FODMAP food may shift it from a low to a medium or to high FODMAP if you have "too much" at once. There are also typos in the shopping list. You end up with a couple of items that you will not use and you'll get to some recipes that call for something that wasn't on the list.
I really wanted to give the book 5 stars, because it's pretty good in that it has some recipes that are INCREDIBLY helpful and tasty (Fish and Chips, how to make your own ketchup, salad dressing, pesto, etc.). However, some are kind of obvious, and I didn't need a cookbook to tell me how to make (a basic salad, and grilled veggies?? are you serious?). It wasn't too expensive and I would recommend it if you're looking to expand your recipes, especially your sauces, dips, dressings and deserts because the store-bought versions usually have onion and/or garlic in them.