About 1 in 4 people with Crohn's get arthritis, or inflamed joints. You may have elbow, wrist, knee, and ankle pain. This type of arthritis doesn't cause lasting damage, and the pain usually goes away when your Crohn's symptoms do. Some people get pain and stiffness in their lower back, which can be more serious and don’t typically go away when the flare does. Your doctor may prescribe medications, physical therapy, and joint rest.