The cause of the inflammatory bowel diseases (IBD), ulcerative colitis, and Crohn's disease, is not known. Studies suggest they are caused by a combination of things, including genes, environmental factors, and problems with the immune system.
There is strong evidence to suggest a genetic basis for IBD, including:
Diet does not cause Crohn's disease. But pay attention to what you eat, because it can help you control your symptoms. Cutting out some foods may help, especially during a flare.
Still, you want to make sure you eat a variety of healthy foods.