DIFFERENTIAL GASTROINTESTINAL EFFECTS OF WHO-STEP III OPIOIDS IN LOW BACK PAIN PATIENTS WITH VS. WITHOUT CONSTIPATION: POST-HOC ANALYSIS OF DATA FROM A 12-WEEK PROSPECTIVE, OPEN-LABEL BLINDED ENDPOINT STREAMLINED STUDY (PROBE-PHA2) First published 22/09/2015 Last updated 02/04/2024 EU PAS number:EUPAS11048 Study Finalised