“…there was 1 prospective controlled study, 13 1 retrospective cohort study, 14 and 10 cross-sectional survey studies [15][16][17][18][19][20][21][22][23][24] (table 1). the studies were conducted at a broad range of medical and surgical centers in sweden, 13 singapore, 14 Germany, 15 14,17,18,20 seven studies, with a total of 308 patients, analyzed the prevalence of chronic constipation, which ranged from 22.2% to 86.7%. 13,14,17,[20][21][22]24 the largest study (n = 59) reported a prevalence of 33.9% (95% Ci, 23.0%-46.8%).…”