If athritis is clearly shown in investigations, treatment of arthritis also responds, there is no doubt the same is causing consistent back pain. Ileostomy doesn t cause arthritic pain. If you change doctor or pain killers, it won t help you. Instead I would advise to my own patients to get the additional support of Ayurveda s pain management oils such as Mahanarayan oil, Mahavishgarbh oil, Mahamash oil or Rumalya liniment of Himalya etc....vast range. Selection of oil by your Ayurveda doctor may be on the basis of condition assessed. Generally the oils are applied after hot fomentation over back for better absorption. It will support you 100%. No side effects. May be little smelly. Hope it gives you hint for immediate future step for better relief.