From a patients perspective it sure sounds like symptoms of a hernia. I had a lot of discomfort when sitting. It seems the logical step would be to repair the hernia while its small especially if you do a non mesh, pure tissue repair Bc you can have better outcome when the hernia is small.
i think it is awesome that you visited the shouldice hospital they are the best when it comes to a non mesh repair.
after recovery from the hernia repair you could see if his pain is gone. If not it is something else. But at least he would of had his hernia repaired