I Have Had Back Pain For Several Months. Went To

I have had back pain for several months. Went to chiropractor for several adjustments and after last adjustment by that vending I couldn't move:(. Only way I could lay was face down was bedridden for 5 days!! Went to dr. He did back X-rays and sent me for MRI! Went over MRI with dr. It's herniated or ruptured disc in L4 down! I have horrible hip pain . Numbness and pain in left calf and numbness in foot with pain! He prescribed me Percocet and Valium and scheduled me another MRI with dye! There is a dark spot on last MRI? What does that mean or what could that be? He mentioned maybe part of disc broke off and might have displaced in my spinal canal pushing on sciatic nerve! Possible surgery I think he said disectemy! My concern is what the dark spot is could it be a tumor? Bone fragment? Or bone spur!