The nuvaring is usually tolerated very well, so having itchiness and soreness down there is not normal. It may be thrush, have you been having discharge? Either way, let the doctor who prescribed the nuvaring know what your symptoms are, you might benefit from antifungal medications. The nice thing about the nuvaring is that it works by delivering medication locally for birth control, and doesnt have to get to the reproductive system through the blood as much as a pill you swallow, and in theory has milder side effects. So, although you can never say its impossible, I doubt the nuvaring is causing your knee pain. What can cause bad knee pain is Crohn s. In fact, arthritis is one of the most common issues outside of the intestines that occur in crohn s patients, ask your gastroenterologist if you think your knee pain is from your crohn s (I imagine you will likely need to be examined in the office for this). The response written above is a medical opinion, and does not substitute an evaluation by a medical professional. I cannot guarantee accuracy in my answer, especially when I cannot physically evaluate you, and do not know your past medical history, all of the medications you are on, your lifestyle habits, etc; therefore I cannot be held liable for any consequences that occur as a result of my opinion.