Does a non obstructing kidney stone still cause severe pain?

Kidney Stones: The pain that occurs as a result of kidney stones comes from one thing and that is obstruction. So, the answer to your question is no. Non-obstructing kidney stones can not be felt at all. However, a stone can sometimes move in and out of an obstructing position. Imaging studies may catch a previously obstructing stone when it is no longer causing blockage (obstruction).