Hemorrhoids

n. swollen blood vessels near the anus

n. abnormally enlarged vein in or near the anus

Hemorrhoids (AmE), haemorrhoids (BrE), emerods, or piles are varicosities or swelling and inflammation of veins in the rectum and anus.
See more at Wikipedia.org...

Hemorrhoids are enlarged veins in the anus or lower rectum. They often go unnoticed and usually clear up after a few days, [more]Hemorrhoids - Community and Resources

Noun
1. pain caused by venous swelling at or inside the anal sphincter
(synonym) haemorrhoid, piles
(hypernym) pain, hurting

(n. pl.)
Livid and painful swellings formed by the dilation of the blood vessels around the margin of, or within, the anus, from which blood or mucus is occasionally discharged; piles; emerods.