My back is fused. Just had a head on auto collision. Now I have loss of use left arm and hand"intermittent " and terrible back pain leg pain foot pain internal problems can't tell if im pooping or peeing till it's to late. I drop things I can't remember th

See you Doc. These are all serious issues and may represent a spinal cord injury or significant nerve compression. The bowel and bladder issues concern me the most. You need to be checked out.
You need to. Follow up with your doctors. A team approach between your internist and orthopedist or neurologist is in order. Good luck and speedy recovery.