Low Anterior Resection Syndrome (LARS)

Abstract

Rectal cancer surgery has undergone significant advancements, with a shift towards sphincter-sparing operations due to improved surgical techniques and neoadjuvant treatments. However, this has given rise to low anterior resection syndrome (LARS), characterised by various bowel functional abnormalities adversely impacting patients’ quality of life. This chapter delves into the definition, risk factors, diagnosis and current treatment recommendations for LARS. The new consensus definition of LARS incorporates a range of symptoms, and their impact on mental, emotional and social well-being. The widely accepted LARS score, a patient-reported outcome measure, aids in standardising reporting but has limitations. LARS has a multifactorial aetiology involving colonic dysmotility, iatrogenic nerve damage, neorectal reservoir dysfunction, recto-anal inhibitory reflex loss, and anal sphincter dysfunction. Various risk factors, including tumour location, anastomotic leak, diverting stoma, pelvic radiotherapy and surgical approach, all contribute to LARS development. Treatment modalities encompass conservative measures such as dietary modifications, probiotics and medications, while advanced treatments include pelvic floor rehabilitation, transanal irrigation, neuromodulation and, ultimately, surgery for refractory cases. Although research has improved our understanding of LARS, further studies are essential to increase prevention and improve treatment strategies.