It would be more accurate to say that steriods have an effect on inflammatory bowel disease. Steriods reduce inflammation - that is their primary function in the body. So they will reduce the inflammation (swelling, irritation) of the bowel.
But reduction of inflammation, even when it creates a temporary sensation of feeling better, is very dangerous. Inflammation is often the body's way of protecting against the growth of infection, and it supports healing. Eliminating infection can allow disease to flourish. It can also create many other imbalances. As a general rule, steroids are very dangerous, even for medical purposes.