He had a huge day at the office after being on the road for 4 days. Then he had a 2 hour wait for his flu shot...they were just doing #6 when we arrived and he was #35...only 2 nurses working. We were sitting in a drafty lobby, his back started to ache. I thought it was from the drive, and lack of exercise. Later last night the pain may have revealed itself...possible kidney stone movement! Poor guy! I hope things settle down with some bed rest.