Right Colon Enema to Improve Bowel Preparation Quality During Colonoscopy

Colonoscopy is a test that lets doctors look inside the large bowel to find and remove growths called polyps, which can develop into bowel cancer. Before the test, people take a bowel preparation to empty the bowel. Even so, the right side of the bowel is often not clean enough, and polyps there can be missed. This study is testing whether giving an enema (a small amount of fluid passed into the bowel) during the colonoscopy makes the right side of the bowel cleaner. Participants having a routine colonoscopy at Westmead Hospital or Auburn Hospital will be assigned by chance to either receive the enema during the procedure or to have their colonoscopy in the usual way. Neither group takes any extra preparation at home. The researchers will compare how clean the right side of the bowel is in each group, using a standard scoring system, and will also look at how many polyps are found. The aim is to find out whether this simple step improves the quality of colonoscopy.

Inclusion Criteria: * Age 18 to 85 years * Undergoing elective full colonoscopy for any indication * Successful caecal intubation achieved during the procedure, confirmed prior to randomisation * Able to provide written informed consent Exclusion Criteria: * Emergency colonoscopy * Known inflammatory bowel disease with active colitis in the examined segment * Familial polyposis syndromes * Prior major right hemicolectomy or altered anatomy preventing standard right colon assessment * Known obstructing colorectal malignancy precluding safe progression or adequate examination * Pregnancy * Renal failure (eGFR less than 30 mL/min) * Previous sodium phosphate enema within the preceding 24 hours * Contraindication to sodium phosphate administration as determined by the treating endoscopist