A randomized, double-blind, placebo-controlled trial to assess the essentiality of acid inhibitors for abdominal pain after gastroscopic mucosal biopsy - YANG, Jie; LING-HU, En-Qiang; LI, Hui-Kai; FENG, Xiu-Xue; ZHANG, You; BU, Bao-Guo; WU, Bei (Turkish Journal of Gastroenterology, 2013)