Are you sure that your condition is Ankylosing Spondylitis (AS)? Have you been systematically evaluated and diagnosed? AS is an autoimmune disease characterized by lower back pain and deformity of spine. Usually patients with AS also have positive HLA-b27. Usually it is considered that genetic background like positive HLA-B27 as well as environmental factors such as intestinal infection contributed to the occurrence of AS. Usually, AS is treated by NSAIDS, immunosuppressants, or biologic agents. Based on your condition, you need to see a rheumatologist for systematic evaluation.