The inferior mesenteric vein is one of the major veins that drain blood from the gastrointestinal tract. However, there are several synonyms that can be used to refer to this vein. These include the left colic vein, the sigmoid vein, and the superior rectal vein. The left colic vein is named for its location near the left colon, while the sigmoid vein is named for its location near the sigmoid colon. The superior rectal vein is named for its proximity to the rectum. While these terms are often used interchangeably, it is important to note that each has a slightly different course and may have different clinical implications.