Chronic Idiopathic Constipation Treatment Market (By Drug Class: Serotonin-4 [5-Ht4] Receptor Agonist, Guanylate Cyclase-C Agonist, Laxatives, Stimulants, Others; By Route of Administration: Oral and Rectal; By Distribution Channel) - Global Industry Analysis, Size, Share, Growth, Trends, Revenue, Regional Outlook and Forecast 2021-2030