Efficacy was evaluated based on the following measurements:
Brief Pain Inventory—Short Form (BPI-SF), a patient-rated
scale based on ‘least’, ‘average’ and ‘worst’ pain felt over the
previous week [30]; Bowel Function Index (BFI) a comprising
three components (ease of defecation, feeling of incomplete
bowel evacuations and personal judgement of constipation)
[31, 32]; patient assessment of constipation (PAC-SYM) [33];
rescue medications (Oxy IR and laxative); number of bowel
movements; health status (EuroQol EQ-5D) and quality of life
(QoL) (European Organisation for Research and Treatment of