It would be most important to distinguish your problem by its full diagnostic name. You refer to "IBS", which stands for Irritable Bowel Syndrome. Steroids are rarely used for this condition. If the letters are "IBD", which stands for Inflammatory Bowel Disease - Crohn;s disease, ulcerative colitis, collagenous colitis, or lymphocytic colitis - that is quite different. However, note that both conditions (IBS and IBD) can exist in the same person and often do.
Steroids taken orally, such as prednisone, are used with great caution these days because of so many established side effects. They can be life saving in acute management, while transitioning to other therapies. These other therapies are considered 'steroid sparing' and are the cornerstone of current therapy world-wide. Long-term steroid use should be avoided if at all possible. Ask your doctor to clarify for you the disease you have and how the diagnosis was established. If you haven't seen a gastroenterologist recently, it may be a good opportunity to review your case with one.