Now have another herniated disk above fusion. i am experiencing back leg and knee pain numbness and tingling bladder and bowel retention?

Sorry about recurren: Unfortunately this happens occasionally after back surgery best to get evaluated by the treating surgeon depending on how much time since the last surgery you can try conservative treatment and see if it works it is concerning that you have bladder and bowel symptoms but some times they may improve with conservative treatment as well good luck.

Cauda Equina: Inability to urinate is an emergency. I would make sure you don't have what is called cauda equina syndrome. Unfortunately this requires surgery to correct. Ofetn times the nerves are just bruised abit and the signals aren't being sent quick enough, you may need an epidural steroid injection to relieve this irritation. Either way, i would see a pain/spine specialist to evaluate your options.

Can occur: A well done study of back fusions, showed high risk of arthritic deterioration at 5 yrs, both above and below, site of fusion. So, this is NOT an uncommon outcome from such surgery. Would focus on conservative approaches if possible, and work with physical therapist. Also, get additional opinions from spinal surgeons.