Rectum

The rectum is part of the distal part of the gastrointestinal tract; it is between the sigmoid colon and anus.

Definition

Abdominoperineal resection specimen showing the rectum.

Pathologist generally agree that: the rectum starts/sigmoid ends at the place where serosa ends on the posterior aspect of the bowel (peritoneal reflection).

Note:

• There are several definitions for the rectum.
  • In a survey of surgeons:
  • 67% defined it by an anatomical landmark
    • 35% of all respondants considered the peritoneal reflection the proximal boundary of the rectum.
  • 30% defined the proximal boundary as a distance from the anal verge.

See also

• Colon.