Inferior rectal veins explained

Inferior rectal veins
Latin:	venae rectales inferiores
Drainsfrom:	Rectum
Drainsto:	Internal pudendal vein
Artery:	Inferior rectal artery

The lower part of the external hemorrhoidal plexus is drained by the inferior rectal veins (or inferior hemorrhoidal veins) into the internal pudendal vein.

Veins superior to the middle rectal vein in the colon and rectum drain via the portal system to the liver. Veins inferior, and including, the middle rectal vein drain into systemic circulation and are returned to the heart, bypassing the liver.^[1]

Pathologies involving the Inferior rectal veins may cause lower GI bleeding. Depending on the degree of inflammation, they are given a grade level ranging from 1 through 4.

Notes and References

1. van Hoogdalem . Edward . de Boer . Albertus G. . Breimer . Douwe D. . Pharmacokinetics of rectal drug administration, Part I. General considerations and clinical applications of centrally acting drugs . Clinical Pharmacokinetics . July 1991 . 21 . 1 . 14 . 10.2165/00003088-199121010-00002 . 18 March 2024 . 0312-5963 . The superior rectal vein, perfusing the upper part of the rectum, drains into the portal vein and subsequently into the liver On the other hand, the middle and inferior rectal veins drain the lower part of the rectum and venous blood is returned to the inferior vena cava..