I have symptoms of ankylosing spondylitis . i want to avoid a life of prescription drugs. can the disease progression be managed with exercise?

Possibly: I can't promise but practicing Yoga has been shown to help with arthritis and other debilitating progressive degeneration of the spine. Best to consult with a physiatrist, a doctor who specializes in sphysical medicine and rehabiltaion. I would stay away from any high impact exercise to be on the safe side, avoid jogging, or mix martial arts and such.

Symptoms or diagnosi: Of ankylosing spondylitis (AS)? I highly suggest you to be seen by a rheumatologist to rule out the disease itself. If you have AS then it is almost impossible to avoid medical therapy as it is a type of autoimmune condition. Although exercise is recommended and focus on increase range of motion esp for your spine.