Objective:To assess the differences in multidimensional clinical manifestations between patients with irritable bowel syndrome (IBS) matching the Rome Ⅲ criteria but not matching Rome Ⅳ and IBS patients matching the Rome Ⅳ criteria, among patients diagnosed with IBS according to Rome Ⅲ criteria.Methods:From November 2016 to October 2017, a total of 472 IBS patients admitted to six hospitals were selected, which included Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology (139 cases), Sir Run Run Shaw Hospital, School of Medicine of Zhejiang University (95 cases), the First Affiliated Hospital of Dalian Medical University (96 cases), the Affiliated Hospital of Guizhou Medical University (90 cases), the People′s Hospital of Guangxi Zhuang Autonomous Region (20 cases), and the Second Affiliated Hospital of Xi′an Jiaotong University (32 cases). The 472 IBS patients were divided into the group that matching the Rome Ⅳ criteria (Rome Ⅳ group), and the group that matching the Rome Ⅲ criteria but not matching the Rome Ⅳ criteria (Rome Ⅲ group). The basic characteristics (IBS course, post-infectious IBS, history of smoking or drinking, etc.), abdominal symptoms, and defecation-related symptoms of two groups were compared and analyzed by face-to-face questionnaires. Multi-dimensional clinical manifestations assessment was completed by questionnaires, which included gastrointestinal symptom rating scale (GSRS), irritable bowel syndrome-severity scoring system (IBS-SSS), irritable bowel syndrome-quality of life (IBS-QOL), and hospital anxiety and depression scale (HADS). Independent sample t-test, rank sum test, and chi-square test were used for statistical analysis. Results:There were 344 patients (72.9%) in Rome Ⅳ group and 128 patients (27.1%) in Rome Ⅲ group. The IBS course of patients in Rome Ⅳ group was longer than that in Rome Ⅲ group (3.0 years (7.0 years) vs. 2.0 years (5.7 years)), and the difference was statistically significant ( Z=-2.73, P=0.006). The GSRS scores of loose stools and abdominal pain of IBS patients in Rome Ⅳ group were higher than those in Rome Ⅲ group, and the GSRS scores of increased exhaust and abdominal distension of IBS patients in Rome Ⅳ group were lower than those in Rome Ⅲ group (3.0(2.0) vs. 2.0(4.0), 3.0(2.0) vs.1.0(2.0), 1.5(3.0) vs. 2.0(3.0), 1.0 (3.0) vs. 2.0(3.0)), and the differences were statistically significant ( Z=-2.48, -9.90, -2.11 and -2.06, P=0.013, <0.001, =0.035 and =0.040). The proportions of fatigue and dizziness of IBS patients in Rome Ⅳ group were higher than those in Rome Ⅲ group (58.4% (201/344) vs. 43.0% (55/128), 30.8% (106/344) vs. 29.7% (38/128)), and the differences were statistically significant ( χ2=8.37 and 12.36, P=0.004 and <0.001). The scores of anxiety and depression subscales of the HADS of IBS patients in Rome Ⅳ group were higher than those in Rome Ⅲ group (6.5 (6.8) vs. 6.0 (6.0), 5.0 (6.0) vs. 3.0 (5.0)), and the differences were statistically significant ( Z=-2.58 and -2.40, P=0.010 and 0.017). The scores of IBS-SSS scale, abdominal pain severity, abdominal pain frequency, and impact on quality of life of IBS patients in Rome Ⅳ group were all higher than those in Rome Ⅲ group (249.5 (108.0) vs. 177.0 (111.8), 50.0 (25.0) vs. 20.0 (30.0), 50.0 (70.0) vs. 10.0 (30.0), 66.0 (42.0) vs. 42.5 (34.0)), and the differences were statistically significant ( Z=-7.79, -9.64, -10.65 and -2.48, P<0.001, <0.001, <0.001 and =0.013). The score of IBS-QOL for behavioral disorder of IBS patients in Rome Ⅳ group was lower than that in Rome Ⅲ group (74.5±21.6 vs. 79.2±17.7), and the difference was statistically significant ( t=-2.22, P=0.027). Conclusion:The clinical symptoms of patients mathching the Rome Ⅳ criteria are more typical and severe, as compared with those of IBS patients matching the Rome Ⅲ criteria but not matching the Rome Ⅳ criteria.