The primary purpose of the protocol is to evaluate the safety, efficacy, and tolerability of MOA-728 in subjects with Opioid-Induced Bowel Dysfunction (OIBD) with associated chronic non-malignant pain.

Inclusion Criteria:

• Adult outpatients with opioid-induced bowel dysfunction and chronic non-malignant pain.
• Taking oral, transdermal, intravenous, or subcutaneous opioids.
• Willingness to discontinue all pre-study laxative therapy and utilize only study permitted rescue laxatives.

Exclusion Criteria:

• History of chronic constipation before the initiation of opioid therapy.
• Other GI disorders known to affect bowel transit.
• Women who are pregnant, breast-feeding, or plan to become pregnant.