If you've gone without drinking soda for 5 months but start drinking it again & experience gas, bloating & discomfort/pain from it, is it best to stop drinking it again? or could your body eventually get used to the soda again so the issues go away?

The bloating that occurs with most sodas reflects the natural release of the carbonation in most such drinks. The release of this gas (CO2) combines with air you swallow during feeds & gas released by germs in the gut to produce bloating. I find it an expected outcome whenever the combination of these factors occur. If this bothers you just don't drink sodas.