What are some good exercises to help relief back-pain if you have ankylosing spondylitis?

Flexibility-Core. You want to do a complete and diverse program beginning with flexibility and postural ones to avoid becoming "fused" in a bent over position leading to increased muscular pain in that case. Cardiovascular and core strengthening will help in general while producing your own pain relievers called endorphins.
Extension exercises. Consider exercises that extend your spine. Consult a physician and a pt.

Related Questions

How do you treat back pain from ankylosing spondylitis?

Several ways. This is a problem that necessitates a face-to-face meeting with your doctor. This will allow him/her to examine you, ask specific questions. And possibly order tests to find out what's wrong and what to do to help you.

Can ankylosing spondylitis begin with neck pain? 1yr after my neck pain started now I have low back pain and bony erosions in si joint x-ray. I'm 29

Yes. While most cases of as start in the lower spine it may first be noted in the cervical area. This is especially true in psoriatic spondylitis. Make sure you are followed by a rheumatologist to confirm diagnosis and get proper care.
Yes. It can start anywhere in the spine but most commonly begins in the sacroiliac a and lower back.

I have uveitis, fatigue, photophobia, ulcer, back pain, stiff neck, joint pain, pain in the night, etc. Do these symptoms confirm ankylosing spondylitis?

No. There are a number of disorders that can cause your symptoms, ankylosing spondylitis being one of them. Ankylosing spondylitis can be diagnosed with a blood test... Hlab27. A rheumatologist is best qualified to sort out what's going on with you.
Sounds like it. Bechet's also is in the list if the ulcers you describe are in the skin.