Oh gosh yeah that is almost the opposite of what the docs will tell him. The red meat one is the debatable topic but almost all doctors will tell him to avoid greens like that like the plague.
This is pretty much the stock playlist for foods they will tell you
https://www.medicalnewstoday.com/articles/317836#foods-to-avoid
The red meat is the one that is "controversial" but he should find unanimous support around avoid a lot of those other items. Fruit without skin, no green leafy veggies. etc. Huge triggers for most. Some fruit (fruit without skin) and low fiber veggies, etc. tend to be ok.
I would tell him to at least poke around on keto and carnivore adjacent diets. There have actually been several legit studies on it and it holds a lot of promise. Even docs that are against carnivore have started to prescribe it to chron's and UC patients occasionally. Best of luck to him man hope he finds the right program, quickly.
