<p><b>BACKGROUND</b>Despite 100 years of research, the continued absence of well-established risk factors impedes the diagnosis and treatment of interstitial cystitis/painful bladder syndrome (IC/PBS). We aimed to identify risk factors in patients with lower urinary tract symptoms (LUTS) without urinary tract infection or benign prostate hyperplasia in China.</p><p><b>METHODS</b>A total of 397 outpatients with LUTS presenting for care to urology clinics in several hospitals throughout China were surveyed using a standardized questionnaire and validated outcome measures. The definitions for painful bladder syndrome based on the O'Leary-Sant interstitial cystitis symptom and problem indices were used. The prevalence of possible risk factors was analyzed using the Fisher's exact test and Pearson chi-square test, and multivariate predictive models were developed using binary Logistic regression methods.</p><p><b>RESULTS</b>Of those multi-centre patients surveyed, including 174 women and 223 men, 41% (162/397) met criteria for painful bladder syndrome. There was a significant difference between women and men (55% (95/174) vs. 30% (67/223), P < 0.001). Women with IC/PBS were more likely than those without IC/PBS to report a history of gynecological infections (odds ratio (OR): 2.85; 95% confidence interval (CI): 1.32 - 6.16, P = 0.007), intake of stimulatory foods (OR: 3.52; 95%CI: 1.50 - 8.30; P = 0.004), irritable bowel (OR: 3.46; 95%CI: 1.22 - 9.80; P = 0.014) and/or anorectal disease (OR: 2.68; 95%CI: 1.12 - 6.40, P = 0.023). After adjusting for confounding factors, bladder pain was significantly associated with stimulatory foods (OR: 3.85; 95%CI: 1.58 - 9.36, P = 0.003) and anorectal disease (OR: 2.76; 95%CI: 1.09 - 7.04, P = 0.03) in women. Caffeine beverage intake (OR: 3.54; 95%CI: 1.54 - 8.12, P = 0.003) was identified the only modifiable association noted in multivariate analysis of men.</p><p><b>CONCLUSIONS</b>We found that stimulatory foods, anorectal disease and caffeine beverages are potential risk factors for IC/PBS. Further studies are necessary to determine their role in the pathogenesis of this disorder.</p>