I'm a 36-year-old female, very healthy overall, normal weight, nothing remarkable in my medical history. About a month and a half ago, I started waking up with a slightly stiff lower back, but soon after getting up, I'd limber up and be fine. Over the past 4 to 5 weeks, the morning pain and stiffness in my lower back has gotten worse. It feels like my spine doesn't want to bend. On a scale of 1 to 10, the pain is probably a 5 or 6. Once I stand up and start moving around, the pain gradually decreases (to a 2 or 3 on the pain scale), however, it doesn't fully go away. Although the pain is always in my lower back (lumbar region, just above my tailbone), sometimes I feel it more on the right side; sometimes on the left. At times it feels like a dull ache in the muscles on either side of my spine; other times it feels like maybe the spine itself is hurting. Walking and moving and standing help the pain. Sitting on a hard surface, or sitting for any length of time, makes it worse. I have no radiating nerve pain, numbness, or tingling. No bladder or bowel problems. I finally went to see a doctor, and she immediately thought of ankylosing spondylitis. She did a variety of movement tests (I laid down, she lifted my legs up, etc.) and told me that she thought the pain was mechanical and not inflammatory. She gave me some back exercises and stretches to do, and those definitely help the pain. She also said that I have extremely tight hamstrings, so I'm doing hamstring stretches as well. I should also mention that my father was diagnosed with osteoarthritis in his 30s and now has severe degenerative disc disease in his lower back. And I have no family history of autoimmune disorders. If it's relevent, I did experience IBS all throughout my last pregnancy, which was 3 years ago. The IBS went away after I had my second child and has not returned. I did pull a muscle in my upper back two months ago after we moved to a new home and I had done some lifting and reaching while I was unpacking, but that has gone away. I have two young children (2 and 4 yrs) and with the 2-year-old, I am constantly picking her up and carrying around, lifting her into her high chair, lowering her into her crib, etc.

I should also mention that I finally took 440 mg of Aleve yesterday, and that helped the pain. I also took 220 mg before bedtime and woke up with significantly less pain and greater range of motion in my spine.

After reading about ankylosing spondylitis, I am now terrified that this is what I have, despite what the doctor says. My fear is that I may be in the very early stages of the disease and that the iritis and other bad symptoms are yet to come. What other conditions might present with lower back stiffness in the morning that responds well to movement and NSAIDs? I am supposed to return to my doctor after 4 weeks if the pain continues, and she would refer me to physical therapy. So far, the pain has not improved (with the exception of when I took the NSAIDs) and, if anything, is getting slowly worse. I'm so scared...just hoping that this might be something that's not degenerative and chronic.

Thank you.