Impact of Acetic Acid-Indigo Carmine Chromocolonoscopy on Proximal Sessile Serrated Lesions

Inclusion Criteria: * Patients whose age are between 45-85 * Patients who have indications for screening * Patients who have signed inform consent form. Exclusion Criteria: * Patients undergoing surveillance colonoscopy after polypectomy or therapeutic colonoscopy for known polyps * Patients with a history of colonoscopy within the past 5 years * Patients with highly suspected or confirmed colorectal cancer * Patients with alarming signs or symptoms: hematochezia, melena, unexplained anemia, weight loss, abdominal mass, positive digital rectal examination * Pregnant or breastfeeding women * Patients with gastrointestinal obstruction * Patients with inflammatory bowel disease, colonic polyposis, or melanosis coli * Patients with coagulation disorders or who have taken antiplatelets or anticoagulants (e.g., aspirin, warfarin) within 7 days before colonoscopy * Patients currently participating in another clinical trial or who have participated in another clinical trial within the preceding 60 days * Patients with failed cecal intubation for any reason (e.g., obstructing lesion, intolerance of the procedure) * Patients with an Aronchick bowel preparation score \>3 at colonoscope insertion, indicating inadequate preparation requiring a repeat bowel preparation * Patients who have used bowel preparation agents not recommended by guidelines, such as oral sodium phosphate or senna * Patients with known allergy to acetic acid-indigo carmine, brilliant blue dye, or medications related to colonoscopy * Patients with missing essential information in the case report form prior to enrollment