Back Pain from upper part to lower part. No problem in sitting and standing but sometime it causes pain while sitting or some stretching. Doing Yoga and back exercise provides some relief. After X-ray doctor told me that I have sacroiliitis on the left side from birth. So, I should be doing exercise only. It's been 8 months. When I did exercise, it went and then I left doing exercise but then it again came. The pain is more in upper left back and less in lower left back. Not stiffness in neck.