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1- Introduction

2- Anatomical Overview

3- Causes

4- Treatment


Internal hemorrhoids (piles) are prolapses of rectal mucosa (more specifically of the “anal cushions”) containing the normally dilated veins of the internal rectal venous plexus. Internal hemorrhoids result from a breakdown of the muscularis mucosae, a smooth muscle layer deep to the mucosa. Internal hemorrhoids that prolapse into or through the anal canal are often compressed by the contracted sphincters, impeding blood flow.

© image from snell's clinical anatomy

Anatomical Overview

Normal Anatomy

  • Anal Canal: The last part of the digestive tract, approximately 2-4 cm long, which ends at the anus.
  • Hemorrhoidal Cushions: These are normal, vascular structures made of blood vessels, connective tissue, and some muscle fibers. They are found in three main locations in the anal canal:
    • Left lateral (3 o’clock position)
    • Right anterior (11 o’clock position)
    • Right posterior (7 o’clock position)

Types of Hemorrhoids

  1. Internal Hemorrhoids:

    • Located inside the rectum, above the pectinate (or dentate) line.
    • Covered by mucosa, a type of smooth, moist tissue.
    • Typically painless due to their location in the area with visceral innervation (less sensitive).
  2. External Hemorrhoids:

    • Located below the pectinate line, covered by anoderm (a type of skin).
    • These are supplied by somatic nerves, making them more sensitive and often painful.
    • Visible and palpable as lumps around the anus.


  • Engorgement: Increased pressure in the hemorrhoidal veins can cause them to swell.
  • Prolapse: Prolonged straining can cause internal hemorrhoids to extend beyond the anus.
  • Thrombosis: Blood can clot within an external hemorrhoid, causing a thrombosed hemorrhoid.
  • Inflammation: Irritation and swelling can lead to inflammation, causing discomfort and bleeding.
© image from snell's clinical anatomy


  • Straining during bowel movements
  • Sitting for long periods of time on the toilet
  • Chronic diarrhea or constipation
  • Obesity
  • Pregnancy
  • Low-fiber diet
  • Heavy lifting


Conservative Treatments:

  • High-fiber diet: Eating more fruits, vegetables, and whole grains to soften stool.
  • Hydration: Drinking plenty of fluids.
  • Topical treatments: Over-the-counter creams and suppositories containing hydrocortisone or witch hazel.
  • Warm baths: Soaking the anal area in plain warm water for 10-15 minutes two to three times a day.
  • Pain relief: Oral pain relievers such as acetaminophen, ibuprofen, or aspirin.

Medical Procedures:

  • Minimally Invasive Procedures: Rubber band ligation, sclerotherapy, or coagulation (infrared, laser, or bipolar).
  • Surgical Procedures: Hemorrhoidectomy (surgical removal of hemorrhoids) or hemorrhoid stapling.
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