(7)sample size estimation: according to Hyun-Soo Kim et al: a randomized controlled study of an GASTROINTESTINAL ENDOSCOPY: cold snare versus hot snare polypectomy for the complete resection of 5-9 mm sized colorectal polyps; a randomized controlled trial, according to the CSP with HSP complete resection rate was (79.1% vs 92.2%), the alpha value of the significant level of 0.05, grasp the degree 1 beta 0.9, according to pass (11.0) software calculated sample size for 300 cases. Taking into account the possible 10% of the rate of loss of access, sample size of 330 cases.