varicosities formed from increased hemorrhoidal venous pressure. Haemorrhoid plexus (rectal veins forming a plexus) are normal anatomical structures within the anal canal. If the haemorrhoid plexus enlarges, it can protrude outside of the anal canal causing symptoms

External: Inferior plexus: below anorectal (dentate) line.

Internal: Superior plexus: above anorectal (dentate) line.

Demographics

• 5% population
• typically adults (>30years)

Aetiology/ Risk Factors

• Straining, constipation, pregnancy, low fibre diet, portal hypertension, prolonged periods sitting, heavy lifting, obesity

Pathophysiology

• increased abdominal pressure → increased venous pressure required to overcome → varicosity of unsupported superficial veins of haemorrhoid plexus

Clinical Features

• Internal haemorrhoids: above the dentate line is endoderm in origin therefore less pain felt
  • Internal haemorrhoids are difficult to palpate and may only be visible on anoscopy.
  • Often painless, bright red bleeding at the end of defecation
    • Blood more on surface of stool or only on toilet paper
  • Anal discharge (containing mucus or faecal debris)
  • Pruritus
  • can be a sensation of rectal fullness or discomfort
  • may or may not prolapse from anal canal
    • classified by degree of prolapse
      • Grade I: no prolapse
      • Grade II: prolapse with defecation, spontaneously reduce
      • Grade III: prolapse and require manual reduction
      • Grade IV: prolapse and irreducible
• External haemorrhoids: below dentate line is ectoderm in origin therefore pain felt
  • Manifestations are similar to those of internal haemorrhoids (i.e., bright red bleeding – don’t bleed as much as internal) pruritus, perianal mass)
  • more pain on defecation
  • May be able feel / see on PR exam
  • severe pain with tense blue swelling: thrombosed external haemorrhoid (aka perianal haematoma)
  • A thrombosed haemorrhoid occurs when a blood clot forms inside a hemorrhoidal vein, obstructing blood flow and causing a painful swelling of the anal tissues.
  • These thrombosed external internal haemorrhoids usually resolve in 2 weeks however will leave skin tags

Investigations

• proctoscopy to confirm