Constipation is common (40-90%) in advanced cancer patients , and has a significant negative impact on quality of life. The aetiology of constipation is often multifactorial in advanced cancer patients. However, it is well recognised that opioid analgesics are a common cause of constipation in this group. The prevalence of opioid-induced constipation (OIC) is stated to be 40-70%, although a recent large study reported an even higher figure.

OIC has been reported to exceed pain in terms of distress caused, and studies have found that some patients choose to reduce or discontinue opioid medication in order to attempt to better control constipation. Moreover, OIC is associated with a variety of physical (gastrointestinal, systemic), psychological and social problems.

This European study follows on from a United Kingdom study, and aims to confirm findings of the previous study in a larger, more heterogeneous sample: it also aims to explore additional strategies to manage OIC. Moreover, the study aims to identify differences in perception of normal bowel habit / constipation, and differences in OIC management in the different European countries. Previous studies suggest that there are cultural differences in people's beliefs about constipation / normal bowel function. The aim of the project is to investigate OIC in a real world / heterogenous group of European patients with cancer.

Inclusion Criteria:

• Age 18 years or over
• Diagnosis of cancer
• Diagnosis of cancer pain or cancer treatment-related pain
• Taking regular opioids for at least one week (i.e. opioid for mild to moderate pain / "weak" opioid; or opioid for moderate to severe pain / "strong" opioid)

Exclusion Criteria:

• Unable to provide consent
• Unable to complete questionnaire

Participants may be inpatients, or outpatients at the study sites. Participants must meet all of the inclusion criteria for the study, and none of the exclusion criteria for the study. Participants must have a diagnosis of cancer and be on regular opioids for at least one week for cancer/ cancer treatment related pain.