• The distal segment of the LARGE INTESTINE, between the SIGMOID COLON and the ANAL CANAL.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• The last 12 centimeters of the colon, through which waste is eliminated from the body.
  Harvard Dictionary of Health Terms
  Harvard Medical Publishing, 2011
• The last several inches of the large intestine closest to the anus.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• The terminal portion of the gastrointestinal tract, extending from the rectosigmoid junction to the anal canal.
  NCI
  U.S. National Cancer Institute, 2021
• The terminal portion of the large intestine extending from the terminus of the colon to the anus or anal canal.
  CDISC Terminology
  Clinical Data Interchange Standards Consortium (CDISC), 2021
• Rectum, terminal segment of the digestive system in which feces accumulate just prior to discharge. The rectum is continuous with the sigmoid colon and extends 13 to 15 cm (5 to 6 inches) to the anus. A muscular sheet called the pelvic diaphragm runs perpendicular to the juncture of the rectum and...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2025