“…The present study underlines the importance of the enrollment source to define the association between BMI and FGIDs. In fact, independently of the country of origin, previous studies associated BMI and organic or functional digestive disorders in cohort patients from different types of enrollment: functional disease recruitment [28], weight loss programs [29], bariatric surgery [20], endoscopic evaluation [27,30], or epidemiological studies [31,32]. In addition, some studies could include control groups [33] but did not separate obese patients according to their BMI [34].…”