superior rectal vein superior rectal vein the inferior mesenteric vein begins in the rectum as the superior rectal vein (superior hemorrhoidal vein), which has its origin in the hemorrhoidal plexus, and through this plexus communicates with the middle and inferior hemorrhoidal veins. superior rectal veinthe bloodvessels of the rectum and anus, showing the distribution and anastomosis on the posterior surface near the termination of the gut. (labeled at top as superior hemorrhoidal vein.)the veins of the right half of the male pelvis.detailsdrains fromrectumsourcehemorrhoidal plexusdrains toinferior mesenteric veinarterysuperior rectal arteryidentifierslatinvena rectalis superiorta98a12.3.12.035ta25130fma15393anatomical terminology the superior rectal vein leaves the lesser pelvis and crosses the left common iliac vessels with the superior rectal artery, and is continued upward as the inferior mesenteric vein.