A prospective, single-center, open-label, randomized controlled study to compare the effectiveness and safety of endoscopic mucosal resection (EMR) and cold snare polypectomy (CSP) in treating colorectal sessile serrated lesions (SSLs) less than 10mm in size.

1. Patients are undergone screening, surveillance, or therapeutic colonoscopy at the Endoscopy department of Gastrointestinal endoscopy center of Huadong hospital affiliated to Fudan University.
2. Randomize patients with suspicious sessile serrated lesions (SSLs) less than 10mm in size into 2 interventional groups based on Random function of Statistical Package for the Social Sciences (SPSS) 20.0, including (1) Group 1: Endoscopic mucosal resection (EMR) and (2) Group 2: Cold snare polypectomy (CSP).
3. Collecting variables which consist of primary and secodary outcomes.

Inclusion Criteria:

• Aged between 35 and 75 years
• Suspected sessile serrated lesions less than 10mm in size in screening, surveillance or therapeutic colonoscopy
• 0-Is or 0-IIa according to Paris classification
• Type 1 according to NICE and JNET classification
• Type II according to pit pattern
• Patients must sign an informed consent form prior to registration in study

Exclusion Criteria:

• Unsuitable for removal by EMR or CSP
• Suspected dysplasia or malignancy
• Recurrent sessile serrated lesions after endoscopic resection
• Familial adenomatous polyposis, Lynch syndrome or serrated polyposis syndrome
• History of inflammatory bowel disease
• Patients taking anticoagulant and antiplatelet agents before the examination
• Severe illness or other high-risk conditions that prevent the patient from cooperating with or tolerating endoscopic therapy
• Refusal to sign the informed consent form or any other factors that are not suitable for enrollment or affect the ability to participate in the study

All collected IPD

1 year after completion of this study

All researchers can require the original data from principal investigator of this study (Email address: arctg4@163.com)