Hi Jingabee16, sorry to hear about your son I was in a similar situation when I was around his age with pain on my hips which alternated.
At one stage I was walking to the toilet pushing an office chair since I could not stand up and eventually spent a month in bed,
Long story short I went to the hospital and I got steroid injections directly into my hip joints. Till this day I never suffered with my hips again. However the disease later moved up my spine after many years.
I am telling you this because if things get out of control, there's something you can try.
Good to hear that diet makes a difference.
All the best to you and your son.
