Objective:To investigate the overlapping prevalence and risk factors of gastroesophageal reflux disease (GERD), functional dyspepsia (FD) and irritable bowel syndrome (IBS) among rural adults in Shaanxi Province.Methods:From February 1 to October 31 in 2019, 12 villages in Shaanxi Province were randomly selected for household questionnaire survey through multistage stratified cluster sampling. A total of 2 423 subjects were enrolled, including 1 037 males and 1 386 females, with age of (45.3±16.9) years old. GERD was diagnosed according to the Montreal criteria, FD and IBS were diagnosed according to the Rome Ⅳ criteria. The overlapping prevalence of the three diseases were calculated. The risk factors for the overlapping of GERD, FD and IBS were analyzed. Multivariate logistic regression was used for statistical analysis.Results:Among the 2 423 subjects, 624 cases had GERD (302 cases), FD (377 cases) or IBS (167 cases), of which 30.77% (192/624) patients had overlap of ≥two diseases. The overlap rates of GERD and FD, GERD and IBS, FD and IBS, GERD, FD and IBS were 2.56% (62/2 423), 1.61% (39/2 423), 2.52% (61/2 423) and 1.24% (30/2 423), respectively. The results of Multivariate analysis showed that female and migraine without aura were positively correlated with the overlap of GERD and FD, FD and IBS, and GERD and IBS (odds ratio ( OR)=3.08, 2.68, 3.66, 7.37, 5.91 and 4.46, 95% confidence interval ( CI) 1.35 to 7.01, 1.35 to 5.30, 1.52 to 8.83, 3.97 to 13.69, 1.78 to 19.60 and 2.01 to 9.92; all P<0.05). Heavy drinking (alcohol intake≥50 g/d (male) or≥30 g/d (female)) was positively correlated with the overlap of FD and IBS, GERD and IBS, and GERD, FD and IBS ( OR=3.69, 4.20 and 4.91, 95% CI 1.19 to 11.48, 1.01 to 17.50 and 1.23 to 19.52; all P<0.05). Heavy smoking (smoking≥20 cigarettes per day) was positively correlated with the overlap of GERD and FD, FD and IBS, GERD and IBS, and GERD, FD and IBS ( OR=3.44, 6.25, 8.27 and 7.04, 95% CI 1.07 to 11.01, 1.60 to 24.44, 1.80 to 38.07 and 1.76 to 28.12; all P<0.05). The educational level of junior or senior high school and age≥60 years old were negatively correlated with the overlap of GERD and FD, FD and IBS, GERD and IBS, and GERD, FD and IBS ( OR=0.47, 0.29, 0.20, 0.05, 0.23, 0.10, 0.37 and 0.16, 95% CI 0.23 to 0.93, 0.09 to 0.95, 0.09 to 0.42, 0.01 to 0.19, 0.09 to 0.60, 0.02 to 0.65, 0.15 to 0.87 and 0.03 to 0.81; all P<0.05). Conclusions:The overlap of GERD, FD and IBS is common and affected by many factors. Female, age≥60 years old, heavy smoking, heavy drinking, low education level and history of migraine without aura are associated with multiple overlaps of GERD, FD and IBS.

Background: Previous studies have found that patients with gastrointestinal diseases have a higher incidence of headache, while migraine patients are often accompanied by gastrointestinal symptoms. Understanding the relationship between diseases can provide new ideas for the study of its mechanism. Aims: To explore the co-occurrence and related risk factors of gastroesophageal reflux disease (GERD), functional dyspepsia (FD), irritable bowel syndrome (IBS) and migraine without aura (MWoA). Methods: A total of 2 696 adult rural residents in Shaanxi Province were investigated by random stratified sampling. MWoA, GERD, FD and IBS were diagnosed based on ICHD-IIIβ, Montreal classification and Rome , respectively. The prevalence of the single disease and overlapping prevalence of MWoA were calculated. The prevalence rates of GERD, FD and IBS between MWoA group and non-MWoA group were compared, and the disease-related risk factors were analyzed. Results: In this study, a total of 2 423 valid questionnaires were collected. The prevalence rates of GERD, FD and IBS were 12.5%, 15.6% and 6.9%, respectively, and the prevalence rate of MWoA was 8.8%. The prevalence rates of GERD (30.5% vs. 10.7%), FD (37.1% vs. 13.5%) and IBS (27.2% vs. 4.9%) in MWoA group were all higher than those in non-MWoA group (P all < 0.001). Multivariate analysis showed that female, hypertension, chronic motor system diseases were positively correlated with GERD, FD, IBS and MWoA. Conclusions: There is a certain association between GERD, FD, IBS and MWoA.