<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, Ive been experiencing a lot of low back pain lately. Could you tell me what could be causing this?  <response>: Based on your symptoms, it seems to be Ankylosing spondylitis, which is a type of arthritis that affects the spine and sacroiliac joints. It can cause stiffness, pain, and even some inflammation in the back. 