Clinical Research Directory

Inclusion Criteria: * Subjects who have advanced colorectal neoplasia\* removed and confirmed by histopathology; * They have received high quality colonoscopies before or during endoscopic resection (defined as a full colonoscopy with successful caecal intubation, and a Boston Bowel Preparation Scale ≧2 in each colonic segment) with no residual colorectal neoplasia; * Aged 18-90 years old; * Written informed consent obtained * An advanced colorectal neoplasia is defined as an advanced adenoma, sessile serrated lesion or non-invasive colorectal cancer (stage Tis or T1a). Advanced adenoma is defined as an adenoma larger than 10mm, and/or with villous component ≥20%, and/or harboring high grade dysplasia. Exclusion Criteria: * Known residual colorectal neoplasia not removed (except hyperplastic polyps); * Contraindications to endoscopic resection due to deep submucosal invasion (stage T1b or above); * Prior surgical resection of colon; * Personal history of hereditary polyposis syndrome or inflammatory bowel disease; * Known pregnancy or lactation; * Immunocompromised status (e.g. on immunosuppressants (except 5-aminosalicylic acid or short term use of corticosteroids \<4 weeks), on chemotherapy, bone marrow or solid organ transplant, human immunodeficiency virus, congenital immune deficiency); * Advanced comorbid conditions (defined as American Society of Anesthesiologists grade 4 or above); * Refusal to undergo surveillance colonoscopy.