Have you tried SCD or GAPS?
These diets help, and, for a significant number of people, bring on some kind of remission for extended periods. They are very similar to the Paleo diet, and, interestingly, very similar diets have been developed independently in a number of countries. Dr. Seigneuret in France, for example. The idea is to eliminate all starches and most sugars. Not easy to do, but if you've had Crohns for a while you've had times when you could eat NO foods at all, I'm sure.
You start with chicken broth, homemade to be sure there's no added sugar or starch. Plus, it tastes great! It's easy to make in a crockpot. Just put in one whole chicken, sprinkle with salt, and about 4 or 5 cups water (depending on size of chicken, but it really doesn't matter). Simmer all day on Low. Strain the broth, salt to taste (lightly). Add coconut milk and/or ginger for healing and taste, if you like. Do whatever you want with the chicken, it's a soggy mess by now. Press all the juices out of the chicken when you strain it.
Drink as much of this as you want, all day. In sips if you're sick. Ginger helps if you have nausea. Nutmeg if you have diarrhea. Coconut oil or milk heals diearrhea, they say. The combination is really delicious.
Even if you don't try the whole SCD or GAPS diet, keep a supply of this broth on hand and have some every day. It freezes well, you can pour it into ice cube trays and then pop them into a ziplock bag after they freeze.
For breakfast or a sweet treat, a smoothie made with papaya, coconut milk, and a little nutmeg and ginger.
Hope this helps.