Inclusion Criteria:  Single polyp, with a diameter of 5-15mm, Written informed consent.  Exclusion Criteria:  Polyps that were not removed en bloc, Underlying bleeding disorder, The platelet count less than 50×10^9/L, Serious cardio-pulmonary, hepatic or renal disease, Intolerance to endoscopy, Other high-risk conditions or disease (such as massive ascites, etc.), Pregnancy.