Anorectal manometry after rectal cancer surgery: physiological insights, clinical interpretation, and limitations

Anorectal manometry (ARM) provides objective physiological information on anal sphincter function, rectal or neorectal sensation, reservoir capacity, and anorectal reflexes after rectal cancer surgery. In rectal cancer surgery, ARM has been used to evaluate functional changes after sphincter-preserving procedures, reconstruction with colonic J-pouch, neoadjuvant radiotherapy, and postoperative bowel dysfunction, including low anterior resection syndrome (LARS). This review summarizes the clinical applications of ARM in rectal cancer surgery, with emphasis on historical and contemporary manometric parameters, their relationship with patient-reported outcomes, and their limitations in postoperative functional assessment. Although several studies have reported associations between manometric findings and bowel dysfunction, the clinical interpretation of ARM remains limited by heterogeneity in measurement protocols, equipment dependency, timing of assessment, and variable correlation with quality-of-life measures. Recent advances, including high-resolution manometry and standardized testing protocols, may improve the reliability and clinical utility of ARM. ARM may provide adjunctive physiological information in selected patients and research settings, but current evidence does not support its use as a stand-alone diagnostic test for LARS or as a routine treatment-decision tool.