The purpose of this study is to compare the effect of naloxegol versus the patient's usual care in treating opioid-induced constipation, as well as the effect on the patient's quality of life and how much pain is experienced. Also, the purpose of this study is to compare whether treatment with naloxegol versus usual care has any impact on the number of hospital or clinic visits or telephone calls to the patient's physician that are related to constipation, and to determine the patient's preference for continuing to receive naloxegol as treatment for opioid-induced constipation.