My son has been complaining about his back hurting for 3 days now and having some constapation. I gave him some teas with laxitive in it and his stool has just started to flow as the should, he say its not stopping his back from hurting, He took one 800mg motrin yesterday and just took one this morning. I am thinking that if he continue to hurt I need to take him to the ER. What do you think?

You should call his primary care doctor before taking him to the ER. It is quite possible he has a kidney stone.