The aim of the project is to investigate opioid-induced constipation (OIC) in a real world / diverse group of patients with cancer.

The objectives of the project are to determine: a) prevalence of OIC; b) clinical features / impact of OIC; c) management of OIC.

StOIC-1 is an observational study, and will involve a single visit (see below for schedule).

The following data will be collected: a) demographic data - age, gender, ethnicity; b) cancer diagnosis; c) opioid medications - drug, formulation, dose; d) laxative medications - drug, formulation, dose; e) other medications; f) Eastern Co-operative Oncology Group performance status

The participants will be asked the following questions:

1. Simple question - "Are you constipated?" [Options - yes / no / unsure]
2. European Association for Palliative Care definition question - "Does the following question describe your bowel function: 'the passage of small, hard faeces infrequently and with difficulty?' [Options - yes / no / unsure]
3. Camilleri definition question - "Does the following statement describe your bowel function: 'a change since initiating opioid therapy from baseline bowel habits that is characterised by any of the following: reduced bowel movement frequency, development or worsening of straining to pass bowel movements, a sense of incomplete rectal evacuation, harder stool consistency?' [Options - yes / no / unsure
4. Rome IV diagnostic criteria for OIC

The participants will also be asked to complete:

1. Bowel function index (BFI). The BFI is a validated, 3 item, patient-reported tool for assessing the treatment of OIC. A BFI score of ≥30 indicates suboptimally treated OIC.
2. Patient Assessment of Constipation - Quality of Life Questionnaire (PAC-QOL). The PAC-QOL is a validated, 28-item, patient-reported tool for assessing the impact of constipation over time.
3. Memorial Symptom Assessment Scale - Short Form (MSAS-SF). The MSAS-SF is a validated, 32 item, patient-reported tool for assessing physical and psychological symptoms in cancer patients.

The participant will also undergo a palliative care specialist assessment for constipation / OIC. The palliative care specialist will be asked to review the patient with regard to their bowel function, and then asked the following questions: a) does the patient have constipation? [Options - yes / no / unsure]; b) (if appropriate) does the patient have opioid-induced constipation? [Options - yes / no / unsure]; c) (if appropriate) does the patient have additional causes of constipation? [Options - yes / no / unsure]; d) (if appropriate) what additional causes of constipation?I](streamdown:incomplete-link)

Inclusion Criteria:

• Age > 18yr; diagnosis of cancer; diagnosis of cancer pain; receipt of regular opioids for at least one week

Exclusion Criteria:

• Inability to give informed consent; inability to complete questionnaire

1000 subjects that are either inpatients or outpatients at study sites (hospitals and hospices in the United Kingdom)

Currently, there are no plans to make IPD available to other researchers