Low Anterior Resection Syndrome in a Reference North American Sample: Prevalence and Associated Factors

Low anterior resection syndrome (LARS) is a well-described consequence of rectal cancer treatment. Studying the degree to which bowel dysfunction exists in the general population may help to better interpret to what extent LARS is related to disease and/or cancer treatment. Currently, North American LARS normative data are lacking. The aim of this study was to describe the prevalence of bowel dysfunction, as measured by the LARS score, and quality of life (QoL) in a reference North American sample. Quality of life was measured and associations between participant characteristics and LARS were identified.This was a single-institution cross-sectional study of asymptomatic adults who underwent screening and surveillance colonoscopies from 2018 to 2021 with no/benign endoscopic findings. Survey was conducted on select comorbidities, sociodemographic factors, LARS, and QoL. Outcomes were LARS and QoL. Multivariable linear regression accounting for a priori clinical factors associated with bowel dysfunction was performed.Of 1,004 subjects approached, 502 (50.0%) participated, and 135 (26.9%) participants had major/minor LARS. On multiple linear regression, female sex (β = 2.15, 95% CI 0.30 to 4.00), younger age (β = -0.10, 95% CI -0.18 to -0.03), White ethnicity (β = 2.45, 95% CI 0.15 to 4.74), and the presence of at least one of the following factors: diabetes, depression, neurologic disorder, or cholecystectomy (β = 3.54, 95% CI 1.57 to 5.51) were independently associated with a higher LARS score. Individuals with LARS had lower global QoL, functional subscales, and various symptom subscale scores.Our study identified the baseline prevalence of LARS in asymptomatic adults who have not undergone a low anterior resection. These normative data will allow for more accurate interpretation of ongoing studies on LARS in North American rectal cancer patients.