I am considering buying a futon day bed, because I have a bad back, is there a bar like there is in sofa beds?

Posted under sofa futon

I will be sleeping on it often and I need to know if it has bars or wooden rods that will hinder my being comfortable

Yes it has tonz of bars! At least the one i had did…. that's what held the bed up is just a row of bars!
So i am telling you - DO NOT USE A FUTON FOR YOUR BAD BACK! They made me get a bad back!
look for something else!