Evaluation of a Modified Bowel Preparation Regimen in Cirrhotic Patients Undergoing Colonoscopy

Inadequate bowel preparation compromises colonoscopy quality and diagnostic accuracy, and cirrhosis is a recognized independent predictor of poor bowel cleansing. However, no bowel preparation regimen has been prospectively validated or specifically tailored for cirrhotic patients. This multicenter, prospective, randomized, single-blind controlled clinical trial will evaluate whether the addition of adjunctive measures as an intensified bowel preparation protocol improves bowel cleansing quality in adult patients with cirrhosis undergoing elective outpatient colonoscopy. Participants will be randomized 1:1 to receive either a standard bowel preparation protocol, consisting of a 2-litre split-dose polyethylene glycol (PEG) regimen combined with a one-day low-residue diet and clear liquids the afternoon before the procedure (control), or the same split-dose regimen with the assigned adjunctive measures: 15 mg bisacodyl, a 3-day low-residue diet, and clear liquids the day before colonoscopy (intervention). The primary outcome is the proportion of patients achieving adequate bowel preparation, defined as a Boston Bowel Preparation Scale (BBPS) total score ≥6 with no individual segment score \

Inclusion Criteria: * Established diagnosis of cirrhosis, scheduled for elective outpatient total colonoscopy * Age ≥ 18 years * Ability to follow verbal and written instructions in Portuguese Exclusion Criteria: * Urgent procedures * Colonoscopies not intended to reach the caecum * History of any colonic surgery * Absolute contraindication to bowel preparation or colonoscopy * Active hepatic encephalopathy (West Haven grade ≥2) at the time of enrolment * Refractory ascites, defined as ascites unresponsive to maximum diuretic therapy or requiring repeated large-volume paracentesis * Severe hyponatraemia (serum sodium \