The present invention provides a pharmaceutical composition for treating gastrointestinal diseases comprising ranitidine, sucralfate and bismuth subcitrate as active ingredients and a preparation method thereof. According to the present invention, when a combination drug of ranitidine, sucralfate and bismuth subcitrate is prepared, it is possible to address a hygroscopicity problem of ranitidine and increase formulation stability and drug bioavailability by controlling particle sizes of sucralfate and bismuth subcitrate.本發明提供一種用於治療腸胃道疾病的醫藥組合物及其製備方法，該醫藥組合物包含作為活性成分的雷尼替丁、斯克拉非及次枸櫞酸鉍。根據本發明，當製備雷尼替丁、斯克拉非及次枸櫞酸鉍的組合藥物時，其可藉由控制斯克拉非及次枸櫞酸鉍的粒子尺寸而解決雷尼替丁的吸濕性問題及增加製劑穩定性及藥物生物可利用性。
