Lubiprostone (Amitiza®) Vs. Standard Care in Opioid-induced Constipation After Surgery in Inpatient Rehabilitation

Inclusion Criteria: 1. Adult, 18 years old or greater. 2. The patient is able to provide informed consent. 3. Anticipated duration of hospitalization of at least 7 days. 4. Woman of childbearing potential must have a negative serum pregnancy test at enrollment. Exclusions for testing include two years or greater postmenopausal, hysterectomy or tubal ligation. 5. Use of opioid for post-op analgesia following orthopedic surgical procedures as defined as IV, IM, transdermal or PO opioid received within the prior 24 hours of hospitalization for pain control, and expectation that an opioid will be continued for pain control. * Medication may be administered on a PRN (as needed) basis or scheduled basis * One or greater doses has been received within the 24 hours prior to enrollment as determined by medication administration recorded from the acute care facility or RIC MAR. 6. At least one associated symptom of constipation at the time of admission, such as, but not limited to: * Lumpy or Hard stools * Feeling of incomplete evacuation of bowels * Abdominal cramping or pain * Straining with movement of bowels or painful bowel movement effort * Need for manual assistance to have a bowel movement Exclusion Criteria: 1. Known allergy or sensitivity to the study medications 2. Females who are pregnant 3. Diarrhea on the day of admission 4. Diagnosis of Clostridium difficile infection during the current hospitalization 5. Pre-existing medical condition or surgical procedure, which is known to commonly lead to bowel dysfunction such as, but not limited to: * Crohn's disease * Ulcerative colitis * Multiple sclerosis * Cerebral palsy * Spinal Cord Injury * Colectomy * Malabsorption Syndrome * Irritable Bowel Syndrome * Abdominopelvic neoplasm (gastric, colon cancer) * Severe liver disease * Colonic or ileo-colonic resections