There's a lot of people with Crohns and other digestive disorders who have benefited significantly from the SCD/Paleo/Primal and/or GAPS diet.
But everyone's system is different and what works for one does not necessarily work for all.
I do believe that all the chemical and artificial additives that are now found in most of our food products are, at minimum, not very good for our systems, if not downright harmful.
My husband and I do not consume any preprocessed food products, and buy as natural, organic, grass fed, as possible, along with growing our own veggies, without chemical pesticides or fertilizers, etc. Although we don't follow any one specific diet, it's actually pretty close to all of the above, all of which stress cooking from scratch, using as many natural food products as possible.
We've been at this a long time, and our diet is neither restrictive or boring. We have everything down so pat, we don't spend that much time cooking or on prep. work either. There's a learning curve, but once you get past that, it's not all that difficult, time consuming or hard.
We don't eat the same things every day, but rather, create a virtual cornicopia of international cuisine to dine on. Indian curries and filafill, Mexican tamales and salsas, Chinese stir fries, Japanese sushi and sushami, African Fufu, and all kinds of fermented probiotic foods, such as Korean Kim chi, polish sauerkraut, miso, hummus, kombucha, yogurt, and of course, my personal favorite, kefir from the Caucasian mountains of Russia.
We don't usually shop at "Whole Foods"' or health food stores, because they are expensive. Shopping at ethnic supermarkets is far cheaper, and provides a much wider variety of fruits, veggies, and various herbs and spices, not typically found at most supermarkets, and usually, far cheaper as well. We also buy directly from organic farmers, who are easy to find here in the great Midwest.
You can't really go by what works for anyone else though, because everyone's system is so different. About the only way to figure out what works best for you personally, is basically through trial and error.
My husband's chronic colitis and my previously severe allergies have been non issues, for quite some years now. Can't say for sure if that's a result of the changes we made in our diet and exercise habits, or if they just decided to go away on their own.