Low-volume vs High-volume Polyethylene Glycol Based Bowel Preparation for Colonoscopy in People Receiving Hemodialysis

Inclusion Criteria: * prevalent end stage kidney disease on hemodialysis people (on hemodialysis for ≥6 months; either hemodialysis or hemofiltration or hemodiafiltration, received for at least 3 times/week for a minimum duration of 4 hours per treatment session for a minimum of 12 hours/week, according to standard practice for quality hemodialysis in Italy); * inpatients and outpatients with an indication to colonoscopy (e.g. positive fecal occult blood test or fecal immunochemical test, signs or symptoms of colorectal disease, colorectal cancer screening, colorectal cancer surveillance, inflammatory bowel diseases, or inclusion in kidney transplantation waiting list); * signature of written informed consent. Exclusion Criteria: * end stage kidney disease not on hemodialysis (eg. peritoneal dialysis or kidney transplantation); * previous kidney transplantation; * need for colonoscopy in emergency; * previous colorectal surgery; * contraindications to colonoscopy in the opinion of the managing physician; * pregnancy or breastfeeding assessed by dedicated pregnancy tests; * known or suspected hypersensitivity to any components of preparations. * gastrointestinal perforation; * toxic megacolon; * inflammatory bowel disease (such as rectal ulcerative colitis, Crohn's disease) in severe acute phase; * occlusive, sub-occlusive or stenotic forms of the intestine, gastric stasis, dynamic ileus, paralytic ileus; * severe state of dehydration; * phenylketonuria (due to the presence…