Hemorrhoids or haemorrhoids (icon), are vascular

Sinusoid (blood vessel)

A sinusoid is a small blood vessel similar to a capillary but with a fenestrated endothelium. Fenestrations are pores in the endothelial cells that greatly increase their permeability. In addition, permeability is increased by large inter-cellular clefts and fewer tight junctions...

 structures in the anal canal

Anal canal

The anal canal is the terminal part of the large intestine.It is situated between the rectum and anus, below the level of the pelvic diaphragm. It lies in the anal triangle of perineum in between the right and left ischioanal fossa....

 which help with stool control. They become pathological or piles when swollen

Swelling (medical)

In medical parlance, swelling is the transient enlargement or protuberance in the body and may include tumors. According to cause, it may be congenital, traumatic, inflammatory, neoplastic or miscellaneous....

 or inflamed. In their physiological state they act as a cushion composed of arterio-venous channels and connective tissue

Connective tissue

"Connective tissue" is a fibrous tissue. It is one of the four traditional classes of tissues . Connective Tissue is found throughout the body.In fact the whole framework of the skeleton and the different specialized connective tissues from the crown of the head to the toes determine the form of...

 that aid the passage of stool. The symptoms of pathological hemorrhoids depend on the type present. Internal hemorrhoids usually present with painless rectal bleeding

Hematochezia

Hematochezia is the passage of fresh blood per anus, usually in or with stools . Hematochezia is commonly associated with lower gastrointestinal bleeding, but may also occur from a brisk upper GI bleed...

 while external hemorrhoids present with pain in the area of the anus

Anus

The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...

.

Recommended treatment consists of increasing fiber

Dietary fiber

Dietary fiber, dietary fibre, or sometimes roughage is the indigestible portion of plant foods having two main components:* soluble fiber that is readily fermented in the colon into gases and physiologically active byproducts, and* insoluble fiber that is metabolically inert, absorbing water as it...

 intake, oral fluids to maintain hydration, NSAID analgesics, sitz bath

Sitz bath

A sitz bath is a bath in which a person sits in water up to the hips. It is used to relieve discomfort and pain in the lower part of the body, for example, due to hemorrhoids , anal fissures, rectal surgery, an episiotomy, uterine cramps, inflammatory bowel disease, and infections of the bladder,...

s, and rest.