The bowel preparation for magnetic resonance enterography in patients with Crohn's disease: study protocol for a randomized controlled trial. - Dai, Min; Zhang, Ting; Li, Qianqian; Cui, Bota; Xiang, Liyuan; Ding, Xiao; Rong, Rong; Bai, Jianling; Zhu, Jianguo; Zhang, Faming (Trials, 2019)