Atlas of pathophysiology, 2 Edition

Part II - Disorders

Gastrointestinal Disorders

Hemorrhoids

Hemorrhoids are painful, swollen veins in the lower portion of the rectum or anus. They're very common, especially during pregnancy and after childbirth. They result from increased pressure in the veins of the anus, which causes the veins to bulge and expand, making them painful, especially while sitting.

Age Alert

Incidence of hemorrhoids is generally highest between ages 20 and 50.

Causes

·   Straining at defecation, constipation, low-fiber diet

·   Pregnancy

·   Obesity

·   Prolonged sitting

Predisposing factors

·   Hepatic disease, such as amebic abscesses or hepatitis

·   Alcoholism

·   Anorectal infections

Pathophysiology

Hemorrhoids are varicosities in the superior or inferior hemorrhoidal venous plexus. Dilation and enlargement of the plexus of superior hemorrhoidal veins above the dentate line cause internal hemorrhoids. Enlargement of the plexus of inferior hemorrhoidal veins below the dentate line causes external hemorrhoids, which may protrude from the rectum.

Hemorrhoids result from activities that increase intravenous pressure, causing distention and engorgement. Hemorrhoids are classified according to severity.

·   First-degree—confined to the anal canal

·   Second-degree—prolapse during straining but reduce spontaneously

·   Third-degree—prolapse and require manual reduction after each bowel movement

·   Fourth-degree—irreducible

Signs and symptoms

·   Bright red blood on outside of the stool or on toilet tissue

·   Painless, intermittent bleeding during defecation (internal hemorrhoids)

·   Anal itching, vague anal discomfort

·   Prolapse of rectal mucosa

·   Pain

·   Hard, tender lumps near anus

Diagnostic test results

·   Physical examination confirms external hemorrhoids.

·   Anoscopy shows internal hemorrhoids.

·   Flexible sigmoidoscopy reveals internal hemorrhoids.

·   Complete blood count shows decreased hemoglobin level and hematocrit.

·   Fecal occult blood testing is positive for blood in stool.

Treatment

·   High-fiber diet, increased fluid intake, bulking agents

·   Avoidance of prolonged sitting on the toilet; avoidance of straining

·   Local anesthetic agents, hydrocortisone cream, suppositories

·   Warm sitz baths

·   Injection sclerotherapy or rubber band ligation

·   Hemorrhoidectomy

P.183

INTERNAL AND EXTERNAL HEMORRHOIDS

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