I've read the book too and came away thinking there were some good ideas and some that did not fit my UC.
Like the author I think fiber is a problem for UC people in flaring-mode unless it is very gentle fiber (soluble). I found that intaking too much (I eat a lot of nuts) causes too many BM's, not my goal
lol. For the average non-UC American adding more fiber is probably a good idea because most peoples diets don't have enough. UC'ers are different and it's asking too much of an inflammed colon to process too much insoluble fiber. So I'm in agreement with the author about
fiber.
I like his list of good/bad foods for the most part however we part ways when he nixes honey and pears along with all other fructose, high-fructose corn syrup, maltitol, sorbitol and other -ols. Honey has caused me no problems that I can detect, neither have brown pears which are less sweet than most other pears and have soluble fiber that I like. I'm not trying to split hairs because avoiding most fruit and fruit juices has been good for my gut. I could switch from honey to cane sugar easily but don't see the need to stop my one fruit that isn't a problem.
You're right he doesn't cite any case studies. He says "Based on research I have conducted on myself and on my many afflicted patients..." and he is an MD (FWIW).
Calcium supplement? I'm not adding one until I see some solid research on that.
Based on my own research (and I'm NOT an MD lol) this book is not bad at all and probably a bit better for me than SCD. However, like SCD he approves of low-lactose yogurt which I can't eat without symptoms appearing in a day or 2.
I still think everyone needs to keep a food journal and see what their gut tells them. This book is probably a good start.