TOPICS: Inferior mesenteric vein (IMV), splenic vein, portal vein, superior rectal vein, colon, spleen, gastric fundus, liver, hemorrhoids, anorectal varices, cirrhosis, inferior rectal veins, portal pressure, portal system, left gastric vein, superior rectal vein, paraumbilical vein, azygos vein, esophageal vein, left gastric vein, short gastric vein, splenic vein, superior mesenteric vein (SMV), superficial epigastric vein, internal pudendal vein, internal iliac vein, paraumbilical vein, varices of the gastric fundus, esophageal varices