Numbness And Swelling In Legs, Cold Feet, Constipation. Spinal X-ray, Blood Tests Normal. Taking Bisacodyl

hi, I have had numb sensation in my legst, gradually worsening over last couple of months, my feet feel cold all the time even when they are warm to touch. Over the last month I have become constipated and only able to pass anything if I take bisacodyl each night. all recent bloods and lower spinal xray are clear, now been referred to neurologist - any ideaswhat it could be? I have no pain except legs feel swollen and tight, although the are normal