Prevalence and clinical significance of evacuation disorders in patients with low anterior resection syndrome.

Purpose: Low anterior resection syndrome (LARS) manifests with evacuation disorder symptoms and continence problems. However, no prior study has focused on evacuation disorders in patients with LARS. This study investigated the prevalence of evacuation disorders and their association with the LARS score.

Methods: This study included patients with defecation per anus at the time of the survey, which was conducted between November 2020 and April 2021. These patients had undergone anus-preserving surgery for rectal tumors between 2014 and 2019 at a tertiary university hospital. The severity of evacuation disorders and LARS was evaluated using the Constipation Scoring System and the LARS score, respectively. The primary endpoint was the prevalence of evacuation disorders, defined as evacuation difficulty, feeling of incomplete evacuation, and abnormally long time on the toilet. The secondary endpoints were the associations between these symptoms and the LARS score.

Results: Of 332 eligible patients, 238 (71.7%) completed the questionnaire. The overall prevalence of evacuation disorders was 48.3%. The rates of feeling incomplete evacuation, evacuation difficulty, and prolonged time on the toilet were 45.6%, 15.5%, and 8.4%, respectively. Patients with minor or major LARS had a significantly higher prevalence of evacuation disorders than those with no LARS, particularly regarding feeling incomplete evacuation.

Conclusions: Evacuation disorders were present in 48.3% of patients following anus-preserving surgery. Greater severity of LARS was associated with a higher prevalence of evacuation disorders, especially a feeling of incomplete evacuation. Patients should be informed about the potential for both evacuation disorders and continence-related symptoms following anus-preserving surgery.