My 1 Year Old Son Has Been Struggling Severely With

My 1 year old son has been struggling severely with constipation. To the point where he almost has a rectal prolapse EVERY time he poops. I dont know what else to do. Ive tired every juice. Ive used pedialax but it only works when hes pooping. Prunes dont work. I give him lots of water. Do i go to the er? Can his intestines be blocked? His poops are so hard its even hard for me to pull them out or break them apart.