Chronic constipation (CC) is a common gastrointestinal disorder with a varying prevalence depending on the defini-tion used to establish the diagnosis. Overall, 12%–19% of Americans are affected (Am J Gastroenterol 2004;9:750–
759), and CC is the second most common ambulatory diag-nosis made by gastroenterologists. Its pathogenesis derives from a heterogeneous combination of secondary causes—age, medications, electrolyte imbalances, endocrinopathies, and musculoskeletal disorders—as well as primary causes including normal and slow transit constipation and evacu-ation disorders. Despite the variety of etiologies, recent con-sensus guidelines recommend against the use of diagnostic testing in the majority of patients and laxatives are used asboth diagnostic and therapeutic interventions. Classically, physicians and patients alike have had access to multiple over-the-counter formulations, including bulking agents, os-motic, and stimulant laxatives.