My husband is experiencing severe stomach pain. He is withdrawing from hydromorphone use which he was forced to do when he lost both his pills and his future prescriptions. He is not trying to get more pain pills. He just wants some relief. It is almost unbearable. I looked up the withdrawal symptoms and stomach pain isn t listed. He is experiencing other symptoms; i.e., chills, some nausea, extreme pain in back, legs and arms. Why would he be having the stomach pain?