If I remember all my terminology, it means you have a narrowing in your ileum that is impairing the flow. As a result, the tissue before the thickened segment is undergoing a mild ballooning. If they haven't mentioned scar tissue, it may be able to be corrected with anti-inflammatory medication such as prednisone. It is a common first issue with crohn's. It sounds like it is limited in its scope though, so you may be fortunate with that. Hope that it responds well to treatment for you.