Author contributions
T.Z., X.M. and L.X. contributed equally to this article. Z.S. acted as guarantors of the article. Z.S. and C.Y. conceived and designed the study. T.Z. and L.C. collected and analyzed the data. T.Z. wrote the manuscript. C.D. generated the random allocation sequence. L.X. enrolled participants. X.M., L.X., H.J., J.W., W.L., F.J. and B.L. performed the endoscopy. T.Z., X.M., L.X., H.J., L.C., C.D., L.X., J.W., W.L., B.L., F.J., C.Y. and Z.S. had full access to all the data in the study and had final responsibility for the decision to submit for publication.