For the record, even the Crohn's and Colitis Foundation of America - known for being very mainstream and pro pharmaceuticals - says diet does indeed play role in the management of inflammatory bowel disease:
Because Crohn's disease and ulcerative colitis are diseases of the digestive tract, it is only natural that you will have many questions about
diet and nutrition if you have been diagnosed with one of these disorders. First of all, you may be surprised to learn that there is no evidence that anything in your diet history caused or contributed to these diseases. Once you develop IBD, however, paying special attention to what you eat may go a long way toward reducing symptoms and promoting healing.
Connor, yes: there are different diets you can experiment with to see if they give you relief from symptoms and help your gut to heal. I'm on a limited version of the SCD which is basically, paleo... no grains, no sugar, no artificial sweeteners, no dairy. It has made a huge difference for me and I believe it helped me achieve years of remission in combination with probiotics, omega-3 supplementation and other natural approaches.