The goal of this clinical trial is to learn if 3-dimensional (3D) imaging device works to correctly classify colon polyps and adenomas during colonoscopy to guide the selection of proper treatment procedures. It will also learn about the safety of 3-dimensional (3D) imaging device. The main questions it aims to answer are:

Does 3-dimensional (3D) imaging device improve the correct classification as well as size and depth evaluation of polyps and adenomas during colonoscopy using pathology as gold standard? What adverse events do participants experience during colonoscopy and polypectomy?

Researchers will compare 3-dimensional (3D) imaging device to traditional 2-dimensional (2D) imaging device to see if 3-dimensional (3D) imaging device works to improve classification and evaluation accuracy.

Participants will:

Undertake colonoscopy examination and polypectomy using 3-dimensional (3D) imaging device or 2-dimensional (2D) imaging device.

Be followed-up to 30 days to record potential colonoscopy-relevant adverse events.

Inclusion Criteria:

• Aged over 18 years;
• Endoscopically diagnosed with colorectal polyps;
• Signing the written informed consent.

Exclusion Criteria:

• Patients with mental illness or severe functional disorder who cannot cooperate with colonoscopy;
• Patients with severe cardiopulmonary insufficiency;
• Patients with severe coagulation disorders or high bleeding risk (platelets <50×10⁹/L, INR >1.5; discontinuation of antithrombotic drugs should follow the 2012 Japanese Guidelines for Gastroenterological Endoscopy in Patients Undergoing Antithrombotic Treatment and the2017 Appendix on Anticoagulants Including Direct Oral Anticoagulants;
• Patients with severe electrolyte imbalances;
• Patients with acute peritonitis or suspected intestinal perforation;
• Patients with severe inflammatory bowel disease/toxic megacolon;
• Patients with polyposis syndromes (e.g., Peutz-Jeghers syndrome, Cronkhite-Canada syndrome, familial adenomatous polyposis [FAP], Lynch syndrome, etc.);
• Patients with stage 3 or higher hypertension (systolic blood pressure ≥180 mmHg or diastolic blood pressure ≥110 mmHg);
• Patients with untreated severe abdominal hernia, intestinal obstruction, or advanced colorectal cancer;
• Patients with intestinal strictures of any cause;
• Cases requiring only endoscopic submucosal dissection (ESD);
• Pregnancy and lactation.