I have 3 herniated disks and multiple tears on my spinal column. Been off work for over a year and have in the past 5 months been cycling on a regular basis. It has been a progressive improvement since.
In terms of medical treatments there have been a series of cortisone injections from L3 down to my S1 joints. Although painful they do relieve pain in the longer run.
This with the cycling has been great. Lost a lot of weight and have regained an exciting and rewarding hobby in the meantime.
In terms of bikes. I have tried road bikes with drop bars and when pedalling hard on the drops it aggravates my spine to the point of not being able to carry on. Therefore I went to my LBS and test rode a Giant Roam 2. It is comfortable. Can work out pretty hard and enjoy trail riding as well. Although I have now replaced the front shock with a rigid CX fork. There are many hybrids out there. Just jump on a few and see how they go.
I like the Giant Toughroad and their Fastroad models too.
Best of luck.