• Organ with organ cavity, each instance of which is continuous proximally with some rectum and distally terminates with some anus. Examples: There is only one anal canal.
  Foundational Model of Anatomy
  University of Washington, 2017
• The last inch of the large intestine, leading to the anal opening.
  Harvard Dictionary of Health Terms
  Harvard Medical Publishing, 2011
• The terminal section of the alimentary canal, which extends from the anorectal junction and ends at the anal opening.
  NCI
  U.S. National Cancer Institute, 2021
• The terminal segment of the LARGE INTESTINE, beginning from the ampulla of the RECTUM and ending at the anus.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• (anal canal (viewed anatomically)) Organ with organ cavity which is continuous proximally with the rectum and distally terminates with the anus. Examples: There is only one anal canal.
  Digital Anatomist
  University of Washington, 2003
• The anal canal is the most terminal part of the lower GI tract/large intestine, which lies between the anal verge (anal orifice, anus) in the perineum below and the rectum above. The description in this topic is from below upwards, as that is how this region is usually examined in clinical practice.
  Medscape
  WebMD, 2025
• Anal canal, the terminal portion of the digestive tract, distinguished from the rectum because of the transition of its internal surface from a mucous membrane layer (endodermal) to one of skinlike tissue (ectodermal). The anal canal is 2.5 to 4 cm (1 to 1.5 inches) in length; its diameter is...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2025