Chronic Constipation Patient Recruitment

In total, 53 patients with CC were consecutively recruited from the Department of Gastroenterology, the First Affiliated Hospital of Nanjing Medical University, between September 2017 and September 2019. The patients were diagnosed based on the Rome III criteria for CC.^{28 (link)} In all, 31 healthy participants were also recruited from the physical examination center of the same institution and assigned to a healthy control (HC) group. The frequency of spontaneous bowel movements of healthy participants should be more than 3 times per week. Individuals who were pregnant, those who had a history of abuse, and those were on drugs that could affect defecation (e.g. antidepressants, spasmolytics, and opioids, but not hypnotics) were excluded. Subjects with a history of antibiotic treatment or intentional probiotic consumption 1 month prior to starting this study were also excluded. The other exclusion criteria were the presence of structural diseases (e.g. tumor, rectocele, and intussusception) based on colonoscopic or barium enema findings); chronic conditions; and previous gastrointestinal surgery. The reporting of this study conforms to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement.^{29 (link)}