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

The purpose of this study is to assess the efficacy of Lubiprostone (Amitiza) compared to standard care for the treatment of constipation in orthopedic patients receiving opioids for pain control during inpatient rehabilitation. Lubiprostone (Amitiza®) is a locally acting chloride channel activator that increases intestinal fluid, and thus increases intestinal motility. It has been approved for chronic constipation, but not in the setting of opioid-induced constipation. Senna is a stimulant laxative that increases propulsive peristaltic activity of the colon through local effects on the mucosa. Subjects will be compared using from the Patient Assessment of Constipation (PAC) which has previously been found to be a valid and reliable way to measure constipation symptoms and clinical course. (Frank, Kleinman et al. 1999) as well as with other measures of bowel-related symptoms and functional outcomes.