Overweight, History Of Kidney Stones, Soreness In Rib Cage. What To Do?

I m quite overweight and have a history of kidney stones . Recently, I threw my back out starting my snowblower... and after a few days of icing and heating my back, the pain went away. But what has continued has been a soreness in my right back along the rib cage. I noticed that eating less has been a way to have it hurt less. I thought maybe I injured a rib... but I m concerned about my liver and kidney. At the same time, I keep having very strong bouts of gas. For about 2 months I ve been adding juice to me diet (mostly kale, spinach , apple cucumber and lemon drinks made fresh), eating more salads for lunch and walking a lot more. I m down 16 pounds in just under 2 months. I have a long way to go- but this irritating pain has me concerned. I m due for a physical... but looking for a new doctor in my area. I just stumbled upon this sight and thought I d ask. Thoughts on the pain?