What is it?

I struggle with bulimia but not every day (developed the disorder 4 months ago), been noticing stiffness on my left side under my rib. It is more stiff after purging/vomiting. There is some bulging out in the area too, not bad but noticeable. Plan to stop with the bulimia and thinking of doing a Water Fast to heal. Hoping it will greatly reduce or go away with fasting. When I am done, if I can go through with it, I will get checked out by a doctor, but want to try fasting first.
Any ideas what it could be? Think it was there before I developed the bulimia but notice the above symptoms now. Tweet