Colorectal cancer is the 3rd most common cancer, of which about 40% is located in the rectum. Standard treatment for rectal cancer (RC) is low anterior resection, combined with chemoradiation. As 5-year survival improves, functional outcomes are increasingly important, given their negative impact on quality of life (QoL). These  symptoms and their impact on QoL are defined  as Low Anterior Resection Syndrome (LARS).(1)
Several studies investigated risk factors for severe bowel symptoms, solely based on the LARS score. However, this score has limitations, including overestimation of QoL impact, underestimation of evacuatory dysfunction and a lack of granularity regarding  the multidimensional nature of postoperative bowel dysfunction.(2-3)
This study aimed to identify risk factors for severe bowel symptoms using a multidimensional assessment and to evaluate the Dutch MSKCC-BFI.

Patients who underwent Total or Partial Mesorectal Excision (TME/PME) for RC between 2017-2024  were included in this prospective study. Exclusion criteria encompassed a Hartmann procedure, abdominoperineal excision, transanal endoscopic microsurgery, sigmoid resection, preoperative fecal incontinence, neurological disorders affecting bowel function, prior pelvic radiation, or LAR for non-cancer reasons.
Bowel symptoms and associated QoL were assessed using the LARS score, the Memorial Sloan Kettering Cancer Center Bowel Function Instrument (MSKCC-BFI), the Colorectal functional Outcome questionnaire (COREFO), and the Quality of Life Questionnaire-Core 30 (QLQ-C30 QoL-subscale) (baseline). In order to assess test-retest reliability, the MSKCC-BFI was administered a second time one week after the initial assessment. Furthermore, discriminant and construct validity were evaluated. Risk factors were extracted from medical records (Table 1). 
Quantitative data were analysed using Mann-Whitney U and Kruskal-Wallis tests to identify the risk factors associated with bowel symptom severity across  the different questionnaires. Statistical significance was set at p<.05 (two-sided).

A total of 115 patients were evaluated at a median follow-up of 40 months after surgery (range, 4–100 months). Distal tumor height, prior radiotherapy, TME, handsewn anastomosis, inferior mesenteric vein ligation, and having a temporary stoma were associated with more severe bowel dysfunction on both the MSKCC-BFI and COREFO. In contrast, prior radiotherapy and TME showed significant associations with symptom severity on the LARS score. None of the evaluated factors were associated with reduced QoL (QLQ-C30). Age, gender, BMI, smoking status, and anastomotic leakage showed no significant associations with bowel dysfunction across any of the outcome measures (Table 1).
The Dutch MSKCC-BFI demonstrated good test–retest reliability (ICC>0.75) for the total score and all subscales. Median MSKCC BFI scores were 77, 73 and 64 for patients with respectively no, minor and major LARS. Strong correlations were observed between the MSKCC BFI and both the LARS score (rs=–.60) and COREFO (rs=–.84), supporting good construct validity. The MSKCC-BFI also showed clear discriminative ability, with significant differences between patients with or without neoadjuvant radiotherapy (p<.001), proximal versus distal tumors (p=.003), PME versus TME (p < .001), stapled versus handsewn anastomosis (p=.003), and with or without a temporary stoma (p=.005).

First, the MSKCC-BFI and COREFO provided a more granular assessment of postoperative bowel dysfunction than the LARS score. Second, their broader symptom coverage enabled the identification of several additional risk factors. Third, the Dutch MSKCC-BFI demonstrated strong reliability and validity, supporting its use as a robust instrument for evaluating postoperative bowel dysfunction.

Postoperative bowel dysfunction is mainly associated with prior radiotherapy and TME, while additional risk factors – namely lower tumor height, handsewn anastomosis, inferior mesenteric vein ligation and temporary stoma – were identified only by the more comprehensive tools (MSKCC-BFI and COREFO). The Dutch MSKCC-BFI showed strong reliability and validity and provides a more detailed assessment than the LARS score, supporting its use in clinical practice.

Keane C, Fearnhead NS, Bordeianou LG, Christensen P, Basany EE, Laurberg S, et al. International Consensus Definition of Low Anterior Resection Syndrome. Dis Colon Rectum. 2020;63(3):274-84.
Ribas Y, Cayetano L, Ortega-Torrecilla N, Espín-Basany E, Bargalló J, Romero C, Marinello F. Reconsidering the LARS score: a cross-sectional descriptive study exploring complementary screening approaches for low anterior resection syndrome. Int J Colorectal Dis. 2026 Feb 28;41(1):73. doi: 10.1007/s00384-026-05115-9. PMID: 41762235; PMCID: PMC12950008.
Ribas Y, Muñoz-Duyos A. How useful is the LARS score in the evaluation and treatment of LARS? Tech Coloproctol. 2019 Feb;23(2):195-196. doi: 10.1007/s10151-019-01943-w. Epub 2019 Feb 22. PMID: 30796620.