Between January and December 2018, patients who underwent radical surgery for rectal cancer at five institutions in Korea answered the Korean version of the LARS score questionnaire, including an anchor question. Participants were retested once more after 2 weeks. All participants had undergone a curative total mesorectal excision for rectal adenocarcinoma less than 15 cm from the anal verge. Only patients who had no stoma at the time of answering the questionnaire were eligible, including those who previously received stoma takedown (repair). Patients who had undergone abdominoperineal resection or palliative surgery were excluded. Patients who underwent surgery or examinations that could affect bowel function in the time between test and retest were also excluded to prevent test-retest reliability bias.
This study was conducted in compliance with the principles of the Declaration of Helsinki. The study protocol was reviewed and approved by the Institutional Review Boards of participating institutions (IRB No. of the principal investigator: KHNMC 2017-10-009-001). Written informed consents were obtained.