Inclusion Criteria:  Sujects require elective colonoscopy for colorectal cancer screening or polyp surveillance, or investigation of symptoms (e.g. anemia, change of bowel habit, abdominal pain, past gastrointestinal bleeding); Aged ≥18 years old; Written informed consent obtained.  Exclusion Criteria:  Absolute contraindications to colonoscopy (e.g. perforation, intestinal obstruction, unstable cardiopulmonary status); Contraindication or conditions precluding polyp resection (e.g. active gastrointestinal bleeding, significant bleeding tendency defined as platelet <50 × 109/L or INR >2, uninterrupted anticoagulation or dual antiplatelets); Previous colonic resection; Known colorectal cancer or adenoma for staged procedure; Personal history of colorectal cancer; Personal history of polyposis syndrome; Personal history of inflammatory bowel disease; Known pregnancy or lactation; Advanced comorbid conditions (defined as American Society of Anesthesiologists grade 4 or above); Refusal to undergo next surveillance colonoscopy.