SUMMARYChronic constipation is a highly prevalent disorder that is associated with significant direct and indirect costs and has substantial impact on patient quality of life. It is more common among women and non-white populations and is evenly distributed across adult age groups. Constipation is a heterogeneous disorder associated with multiple symptoms and aetiologies.Recent research has increased our understanding of the pathogenesis of this disorder and the central role of the neurotransmitter serotonin in mediating gastrointestinal motility, secretion and sensation. Abnormal serotonin signalling and reuptake appear to play central roles in the symptoms of a subset of patients with chronic constipation. This observation provides a rationale for the use of targeted serotonergic agents for the treatment of chronic constipation. As the role of serotonin in gastrointestinal function is further elucidated and additional candidate drugs are developed, it is likely that serotonergic agents will afford additional treatment options for patients with chronic constipation.This article provides a concise review of the evidence supporting a role for serotonin in the pathogenesis of chronic constipation and a summary of the currently available evidence supporting the use of serotonergic agents for this disorder.
OVERVIEW OF CHRONIC CONSTIPATION
DefinitionThere is no universally agreed upon definition for constipation. Traditionally, doctors have focused on decreased stool frequency, with most accepting a cut-off of fewer than three bowel movements per week as consistent with constipation. Patients, on the other hand, often use the term constipation to describe a variety of symptoms, including straining, bloating, quality of bowel movements (i.e. hardness of stool, ease/difficulty of passing a bowel movement) in addition to decreased stool frequency.