This is a single-arm, open label, multinational, multicentre, prospective, real world observational study of Naloxegol in adult subjects with Opioid Induced Constipation (OIC) in patients receiving Naloxegol in routine clinical practice. Subjects who are receiving Naloxegol (prescribed by their physician according to the SmPC, which recommends that all currently used maintenance laxative therapy should be halted) during the enrolment period may be eligible for enrolment into the study.

The objective of this study is to assess the safety and efficacy of Naloxegol in a real world setting in cancer patients.

The primary safety end point is the incidence of adverse events leading to study discontinuation.

The primary efficacy end point is the response rate assessed in the 4 week observation period. Response is defined as three or more bowel movements (without the use of rescue laxative treatment in the previous 24 hours) per week and an increase of one or more bowel movements over baseline.

Inclusion Criteria:

• Patient ≥ 18 years old
• Patient who is receiving treatment with opioids for at least 4 weeks, and is expected to remain on opioids for duration of study
• Patient with opioid-induced constipation
• Patient in whom the clinician plans treatment with Naloxegol according to routine clinical practice (Naloxegol SmPC recommends that all currently used maintenance laxative therapy should be halted)
• Signing of the informed consent

Exclusion Criteria:

- Patients with colorectal cancer

This study will involve 315 patients (out-patients or in-patients) with Opioid Induced Constipation (OIC) from 32 European hospitals.