Anorectal varices are collateral submucosal blood vessels dilated by backflow in the veins of the rectum.
The shunting of blood and consequential increase of pressure through the collateral veins causes the varicosities.
[6] Haemorrhoids are due to prolapse of the rectal venous plexus and are no more common in patients with portal hypertension than in those without.
[7] Rectal varices, however, are found only in patients with portal hypertension and are common in conditions such as cirrhosis.
[5] Insertion of a transjugular intrahepatic portosystemic shunt (TIPS) has been shown to alleviate varices caused by portal hypertension.