You are asked to take part in this study because you have chronic, non-radicular low back pain. This study is done to investigate the pain relieving effects of the study drug Exalgo (Hydromorphone ER) for people who experience chronic non-radicular low back pain. The purpose of this research is to look at how the study drug can be used to benefit people who experience this type of pain. This is a phase IV study done to study the safety and effectiveness of the drug. At this point the drug has been approved by the Food and Drug Administration and has been studied in more than 2,000 pain patients in clinical trials, including individuals with low back pain. About 36 subjects will take part in this study.