Study Evaluating MOA-728 Oral for the Treatment of OIBD in Subjects With Chronic Non-Malignant Pain

The primary purpose of this study is to evaluate the safety and dose-response relationship of N-methylnaltrexone bromide (MOA-728) by observing spontaneous bowel movements in subjects administered MOA-728 who have chronic pain that is not due to cancer, and who have opioid-induced bowel dysfunction (OIBD).