Opioid-induced Bowel Dysfunction (OBD) Pivotal Assessment of Lubiprostone (OPAL)

Inclusion Criteria: A patient can be considered for eligibility to participate if he/she: * Has been consistently treated for chronic, noncancer-related pain with any oral, transdermal, intravenous, or subcutaneous opioid for at least 30 days prior to screening * Is diagnosed with OBD * Is capable of utilizing an electronic diary to report daily spontaneous bowel movements (SBMs) * Is willing to continue opioid therapy and discontinue the use of laxatives, stool softeners, and other concomitant medications affecting gastrointestinal motility throughout the study Exclusion Criteria: A patient cannot be considered for eligibility to participate if he/she: * Uses opioids for the treatment of cancer-related pain, abdominal pain, mechanical bowel obstructions, bowel disorders, and constipation not arising from opioid use, but instead attributable to dietary, neurologic, congenital, or endocrine disorders, scleroderma, and/or for the management of drug addiction