Low Anterior Resection Syndrome

Regardless of the method chosen for rectal reconstruction (end-to-end, side-to-end, colonic J pouch), 25% to 60% of patients undergoing proctectomy will develop “low anterior resection syndrome” (LARS) in varying degrees of severity.[1][2][3][4][5][6] This syndrome of defecatory dysfunction is defined by a constellation of symptoms that include frequency, urgency, fragmentation (bowel movement within one hour of the last bowel movement), incomplete evacuation, and fecal incontinence. For some patients, LARS decreases quality of life because of “toilet dependence” and fear of leaving the home. LARS is associated with loss of the reservoir function of the resected rectum with impaired capacity and compliance of the neo-rectum[7], iatrogenic internal sphincter injury[8], autonomic nerve injury[9], loss of neo-rectum compliance due to neoadjuvant chemoradiation[6][10], anastomotic leak following rectal resection[11][12], changes in colonic motility following mobilization of the left colon[13], and pelvic floor disease existing prior to surgery.[14][15] Anastomotic height is also a risk factor - 46% of patients with a rectal remnant < 4cm experience major LARS compared to 10% with a rectal remnant ≥4cm.[6][16][17] Patients with a low colorectal/coloanal anastomosis have a lower maximal tolerated volume.[6]