Epidemiology and pathophysiology of low anterior resection syndrome

Low anterior resection syndrome (LARS) is a constellation of symptoms that includes incontinence to flatus and/or feces, urgency, and frequency. LARS affects up to 80% of patients after low anterior resection. The pathophysiology of LARS is complex, and a variety of mechanisms have been proposed. These mechanisms include disruption of autonomic innervation and the rectoanal inhibitory reflex, internal anal sphincter dysfunction, decreased anal canal sensation, and decreased capacity and compliance of the neorectum. As the management of colorectal diseases such as rectal cancer continues to improve, there is a concomitant increase in organ preservation, survivorship, and attention to quality of life. Therefore, recognition and understanding of LARS is key to the diagnosis and treatment of this debilitating disease process.