What are hemorrhoids?
Symptomatic hemorrhoids come from inflammation of the mucosa and interstitial tissue surrounding the normal veins of the anorectum. These veins provide the normal pathway for return of blood from the anus and rectum back through the circulation to the heart. Of importance is the fact that the veins in the rectum drain into the portal circulation and thus to the liver prior to returning to the heart, while the veins of the anus drain directly into the central circulation.
I am frequently asked questions by patients about internal versus external hemorrhoids. The distinction is somewhat artificial as external hemorrhoids are merely the external component of a hemorrhoid that originates internally. The dividing line between external and internal is called the dentate line, which is the point at which rectal mucosa changes to anal skin.
What are Piles?
Piles (haemorrhoids) are swellings that can occur inside and around the back passage (anus) and the anal canal.
The anal canal is the last part of the large intestine and is about 4 cm long. At the lower end of the anal canal is the opening to the outside (usually referred to as the anus), through which faeces pass. At the upper end, the anal canal connects with the rectum (also part of the large intestine).
There is a network of small veins (blood vessels) within the lining of the anal canal. These veins sometimes become wider and engorged with more blood than usual. The engorged veins and the overlying tissue may then form into one or more small swellings called piles.
What are Fissures?
An anal fissure is a cut or tear occurring in the anus (the opening through which stool passes out of the body) that extends upwards into the anal canal. Fissures are a common condition of the anus and anal canal and are responsible for 6% to 15% of the visits to a colon and rectal (colorectal) surgeon. They affect men and women equally and both the young and the old. Fissures usually cause pain during bowel movements that often is severe. Anal fissure is the most common cause of rectal bleeding in infancy.
Anal fissures occur in the specialized tissue that lines the anus and anal canal, called anoderm. At a line just inside the anus (referred to as the anal verge or intersphincteric groove) the skin (dermis) of the inner buttocks changes to anoderm. Unlike skin, anoderm has no hairs, sweat glands, or sebaceous (oil) glands and contains a larger number of sensory nerves that sense light touch and pain. (The abundance of nerves explains why anal fissures are so painful.) The hairless, gland-less, extremely sensitive anoderm continues for the entire length of the anal canal until it meets the demarcating line for the rectum, called the dentate line. (The rectum is the distal 15 cm of the colon that lies just above the anal canal and just below the sigmoid colon.)