Overlap Between Constipation and Gastroesophageal Reflux Disease in Japan: Results From an Internet Survey

BACKGROUND/AIMS: Detailed evaluations of overlapping constipation and gastroesophageal reflux disease (GERD) have not been conducted in Japan. The REACTION-J2 study examined the overlap of these diseases in Japan. METHODS: This internet-based survey recruited participants from general public survey panels. Questions included demographic and medical data and assessments based on validated measures for constipation and GERD. Associations between background factors affecting constipation/GERD overlap, disease measures, and treatment were also evaluated. RESULTS: Among 10 000 survey responses received, functional constipation (Rome IV diagnostic criteria) was reported by 439 participants; chronic constipation (Japanese guidelines) by 3804 participants; and subjective constipation symptoms by 2563 participants. The number of participants with constipation/GERD overlap ranged from 73 to 1533 depending on the criteria used. Regardless of the definition used, all GERD groups had significantly higher odds of being constipated than non-GERD participants the OR (95% CI) for all 9 combinations of definitions ranged between 1.56 (1.21, 2.01) and 2.67 (2.44, 2.92) (all P ≤ 0.001). Straining, hard stools, and sensations of incomplete evacuation and anorectal obstruction/blockage, according to chronic constipation criteria, were common. Participants with constipation/GERD overlap had poorer quality of life (P < 0.001) and worse GERD symptom scores (P < 0.001). The frequency of abnormal stools was highest (P < 0.001) in the constipation/GERD overlap group. In the overlap group, 52.4% and 26.0% used gastric and constipation medication, respectively. CONCLUSION: Individuals with constipation/GERD overlap tend to have worsened symptoms and quality of life.