Internal Hemorrhoid Tissue
Hemorrhoids (US English) or haemorrhoids (UK), are vascular structures in the anal canal which help with stool control. Hemorrhoidal tissue lies within the anal canal and perianal area. It consists of blood vessels, connective tissue, and a small amount of muscle. There are two main types of hemorrhoids: internal and external. Internal hemorrhoids are covered with a lining called mucosa that is not sensitive to touch, pain, stretch, and temperature. They become pathological or piles when swollen or inflamed. Internal hemorrhoids usually present with painless, bright red, rectal bleeding during or following a bowel movement. Other symptoms may include mucous discharge, a perianal mass if they prolapse through the anus, itchiness, and fecal incontinence. Internal hemorrhoids are usually only painful if they become thrombosed or necrotic.