Hi backatcha.Low back pain is pretty common with LD, but you also have to pay attention to your kidneys when you're on abx. We're using an herbal tonic (Wise Woman Herbals Glandular Tonic) to promote kidney health and lymphatic drainage. Seems to be working (no kidney or lymph problems so far) and was recommended by my LLMD and ND.
I had a lot of muscular low back pain that came and went, sometimes lasting for months. It's pretty much completely gone now. Massage and stretching helped a lot.
I used to have fairly dreadful headaches, too. Sometimes they were in the low back of my head, around the occiput; sometimes at the temples, and sometimes I felt like someone had stuck a hot poker through my eyball. And sometimes it felt as if an iron band was tightened all around my head. They would come and go, and sometimes last for months. Pretty much all gone, except for occaisionally, and they only last a day or two at the most now.
My doc's theory was that it was a combination of inflammation of the meninges, blood flow issues, and toxins. My husband had the same thing. Nothing showed up in his MRIs (I never had one done), but I say go with you gut -- if you feel strongly about it, have the MRI done.
About the sideness of the bite/sx -- I have not experienced that.
You probably want to take a look at cholestyramine to reduce the endotoxin load -- but for me the treatment really increased the headache pain at first, so go gently. After my 2nd round of CSM, though, I felt I experienced significant improvement. I still find it very difficult to sort out what tx did what, though, in all honesty.
Good luck.