Hemorrhoids (What are hemorrhoids?)
Etiology and Epidemiology
Hemorrhoids are masses of dilated blood vessels that lie beneath the lining of the skin in the anal canal. They are extremely common and estimated to be present in up to 50 percent of the population by age 50. Hemorrhoids traditionally have been viewed as varicose veins of the rectum. The superior hemorrhoidal veins contain no valves and are vulnerable to overdistention when the person is in an upright position. Additional studies have documented that hemorrhoids actually are composed of spongy vascular tissue with multiple direct arteriovenous connections.
Hemorrhoids usually are classified into two types. Those that occur above the anal sphincter are termed internal hemorrhoids and those that occur below the anal sphincter are termed external hemorrhoids. A person can have both forms at the same time. Although hemorrhoids usually are a chronic health problem, they may cause acute episodes.
External hemorrhoids can be detected by the affected persons. The classic “skin tag” consists of small lumps of fibrous tissue and folds of anal skin that have been stretched by bulging of the hemorrhoids. They rarely bleed and seldom cause pain except when they become inflamed and edematous as a result of thrombosis or subcutaneous rupture of an external vein with hematoma formation. A thrombosed external hemorrhoid may occur suddenly after some form of vigorous exercise or after a severe episode of diarrhea or constipation. The intense pain that accompanies thrombosis is caused by the presence of multiple sensory endings. The hemorrhoids are composed of epithelial tissue.
Internal hemorrhoids are not directly apparent to the person unless they become so large that they prolapse through the anus. Usually they do not reproduce symptoms unless complications occur. Internal hemorrhoids are the most common cause of painless rectal bleeding. The person may notice spotting on the toilet tissue or occasional episodes of spurts of blood that accompany straining at stool. Although the blood loss typically is small, it can deplete iron reserves if it persists over a long period. Pain which can be excruciating occurs with prolapse and thrombosis.
Hemorrhoids or both types usually are asymptomatic unless complications occur. Routinely painful defecation accompanied by rectal bleeding is associated with anal fissure more often than with uncomplicated hemorrhoids. Perianal itching is not an expected symptom, and another cause should be explored. If a painful episode has occurred, the patient may develop problems with constipation in an effort to prevent pain or bleeding associated with defecation. Although hemorrhoids rarely undergo malignant degeneration, constipation and bleeding are symptoms of cancer of the rectum. For this reason all persons with these symptoms should have a medical examination to rule out cancer.
Both forms of hemorrhoids can be managed conservatively if their symptoms are not severe. Conservative management includes a high fiber diet, bulk laxatives, warm sitz baths, and gentle cleansing. If severe pain, bleeding, or thromboses are present, however, more definitive management may be indicated. Treatment options for internal hemorrhoids include sclerotheraphy, cryosurgery, and rubber band ligation, as well as traditional surgical hemorrhoidectomy. Infrared photocoagulation and bipolar diathermy are newer adaptations that can be used to affix the mucosa to the muscle. External hemorrhoids may be managed by evacuating the hematoma.