I Am 65 Years Old. Recently, I've Had Mild Discomfort,

I am 65 years old. Recently, I've had mild discomfort, but definitely bothersome, on the right lower side of my abdomen with a low aching backache. I often feel bloated and have constipation...nothing new for me tho. I have had spinal surgery for a pinched nerve (2013) and a sleeve gastrectomy (2014).. I lost 50 lbs but have gained back 12. I exercise 5 hours a week, and am in pretty good health at this point. Taking hydrocodon relieves the pain of both, but I don't like to take it too much. Can my back be causing both of these problems?