Stress plays a major role in many diseases. When the human body endeaurs stress it has many negative biological effects. A weakened immune system is one effect of stress. IBD depends on the immune system to counter act inflammation.
Stress weakens the digestive system hence, the response against inflammation is very small.
Corticalsteroids would inhibit the body from releasing cortisol in response to stress. This limits the overall affect of stress on the body, especially the digestive system allowing inflammation to be more controlled. Please limit your questions and comments to items pertaining to Physiology , the study of normal function of organs and organ systems within organisms. This site does not deal with diseases. If you are seeking medical advice, you should ask your questions elsewhere.