low anterior resection A surgical procedure that is done to treat cancer of the rectum in which the part of the rectum containing the cancer is removed. The remaining part of the rectum is reconnected to the colon. LAR NCI BBRB Person: Chris Stoeckert, Helena Ellis, Jie Zheng https://www.mskcc.org/cancer-care/patient-education/about-your-low-anterior-resection-surgery surgical procedure