1) Body part 2) Colon 
<anatomy> The rectum and sigmoid colon considered as a unit; the term is also applied to the junction of the sigmoid colon and rectum. ... (05 Mar 2000) ... 
(rek″to-sig´moid) the sigmoid colon and rectum considered as a unit.
Type: Term Pronunciation: rek′tō-sig′moyd Definitions: 1. The rectum and sigmoid colon considered as a unit; the term is also applied to the junction of the sigmoid colon and rectum.
[adj] - of or related to or near the sigmoid colon and the upper part of the rectum
adjective of or related to or near the sigmoid colon and the upper part of the rectum