What causes Crohn's disease and Ulcerous colitis?

This is a tricky one. I would say it's not just one thing causing Crohn's disease. I will list a few things I think are worsening inflammation.

1. Bad sleep. When you sleep poorly, your body will deteriorate, and you will begin experiencing many different problems.
2. An unhappy, stressed life is perhaps what causes most diseases. I have said it before, but I'll repeat it. Live well. Don't stress. If you're in a bad relationship or hate your job, GET OUT. You need to move away from things that make you feel bad.
3. Wrong diet. I say wrong because it's so individual. But I think everyone with a sensitive stomach should stay away from gluten, large amounts of sugar ( avoid anything that has sugar as the first ingredient.), dairy, deep-fried food—bad oils. 
4. SMOKING. I think smoking is awful and f*cks up your immune system. Smoking has to be one of the worst things you can do to your stomach and overall health. If you have Crohn's disease and smoke, you probably don't care all that much. I also think that if you are a miserable person with bad relationships, your body tells you to live differently in many different ways.