Randomized clinical trial evaluating three low-volume preparations for colonoscopy in outpatients with Inflammatory Bowel Disease: the EII-PREP trial

BACKGROUND: Bowel preparation is crucial for colonoscopies in patients with In�ammatory Bowel Disease (IBD). However, data regarding cleansing solutions in this setting are scarce. AIMS: Our aim was to compare e�cacy, safety, and tolerability of three different low-volume preparations in patients with IBD. METHODS: Single-center, randomized, prescriber- and colonoscopist-blinded clinical trial. IBD outpatients undergoing colonoscopy were randomized 1:1:1 to receive 1 Liter-polyethylene glycol-ascorbate (1L-PEG), 2 Liters-PEG or sodium picosulfate (SP). Primary endpoint was e�cacy in terms of percentage of quality cleansing assessed via the Boston Bowel Preparation Scale (BBPS >=6 with segments >=2). Secondary endpoints were e�cacy in terms of total high quality cleansing (BBPS 8 or 9), high quality segmental BBPS (>=2) and patients’ tolerability, symptoms, and satisfaction, assessed by questionnaires before and after colonoscopy. Safety was monitored by adverse event reporting, laboratory evaluation at colonoscopy and telephonic follow-up. RESULTS: 92 patients were included (33 1L-PEG, 28 2L-PEG and 31 SP). No signi�cant differences between preparations were observed in quality or high-quality total BBPS or high-quality segmental BBPS. Complete intake of the solution was higher for SP (p=0,006) and lower for 1L-PEG (p=0,02). Clinically irrelevant hyponatremia was higher in the SP group (p<0,0001). SP instructions were easier to understand from the patient’s point of view (p=0,01). Willingness to retake was higher with SP (p<0,0001) and less for 1L-PEG (p<0,0001). No serious adverse events were reported. CONCLUSIONS: We observed no differences between PEG-based bowel preparations and SP regarding e�cacy in patients with IBD. Complete intake was higher for SP and lower for 1L-PEG. SP and 2L-PEG instructions were better understood and graded, and SP was more