is there another way?

My almost 17 year old son was just diagnosed with spondyloarthritis. He has the HLA-B27 gene. In one year he has gone from playing football & baseball to walking like an 80 year old man who struggles to get through gym class. He was given Nsaids, which now have given him stomach issues. Needless to say, he is pretty depressed.We are going back to see the MD on Monday, who will more than likely prescribe another drug treatment. Has anyone out there had any success with functional medicine?