I Had To Have A Ba Swallow Test Today And

I had to have a ba swallow test today and the radiologist checked (where and how I don't know) and said my last kidney test was "borderline" and that I would have to have the thick barium liquid and not the gel. My GP had not raised this issue when I had the blood tests some 3 or 4 months ago, so is there a problem? I am 71 years of age, and take no prescribed medication though I do take several natural supplements. I am active and feel that I am in very good health for my age. The swallow test was organized because of pain just below the breastbone and 'rumbling' in my stomach, which produces both burping and wind, though no reflux as such.