Dr. Scala's book opens with the quote, "Let thy food be thy medicine", and suggests diet and lifestyle habits that are least likely to cause flare-ups.
For me, some of the things I liked most about Scala's book included: Discussion of the nutritional challenges for people with IBD (vitamins, minerals..); Listings of foods that typically cause problems (including processed foods, sugar, corn, whole nuts, many dairy products...); A lot of information about dark skinned cold-water fish (like salmon) and the therapeutic benefits of their essential oils; The suggestion to keep a food diary to help one confirm what is/is not working, but also to document more than just food (emotions, stress, etc.), serving sizes, environmental factors; "End Of Day" self evaluation - How well did I do today? (a self-critique of food and lifestyle choices).
As someone who follows the SCDiet, many of the foods Scala suggests are contrary to what I follow (i.e., he suggests oatmeal, cornflakes, branflakes as foods that don't cause flare-ups; he suggests these for their low-residue/irritation characteristics but I would not eat them because of the complex carbs they contain and the flare-ups that might result from digesting them) but I choose to recognize this book as very useful nonetheless. One can certainly make one's own adjustments to Scala's suggestions, taking a patient-centric approach to healing. We're all different, and what works for one patient may require modification in another.
I especially agree with Scala's insights into whole-body aspects of IBD, and the way outlook, exercise, stress, love, etc. can play a role in one's condition. If you're going to read his book and consider the realistic concept of achieving intestinal health through diet I'd also suggest Elaine Gottschall's "Breaking The Vicious Cycle", Patel-Thompson's "Listen To Your Gut", and Trenev's "Probiotics: Nature's Internal Healers" as complementary reading.