Rectum

Hemorrhoid

search

Hemorrhoid

  • Definition
  1. Dilation of anorectal vessels
  • Epidemiology
  1. Most common anorectal condition
  2. Affects 50% of patients over age 50 years
  • Anatomy
  1. See Rectal Anatomy
  2. Dentate Line
    1. At midpoint of roughly 4 cm long anus
    2. Proximal to Dentate Line
      1. Lined by columnar epithelium
      2. Shares visceral innervation and typically painless
      3. Internal Hemorrhoids form in this region
    3. Distal to Dentate Line
      1. Lined by squamous epithelium
      2. Somatic innervation and painful
      3. External Hemorrhoids form in this region
  3. Positions for internal and External Hemorrhoids
    1. Right Anterior
    2. Right Posterior
    3. Left Lateral
  • Pathophysiology
  1. Anal venous plexus of submucosal vessels dilate
  2. Results in a focal swelling of rectal mucosa
  3. Connective tissue supporting vessels weakens and allows Hemorrhoid descent and prolapse
  • Types
  1. Internal Hemorrhoids
    1. Above Dentate Line, share visceral innervation and are painless
  2. External Hemorrhoids
    1. Below Dentate Line, and are potentially painful
  • Causes
  • Increase pressure in anal venous plexus
  1. Prolonged erect Posture
  2. Back flow
    1. Abdominal pressure
    2. Constipation and straining at Defecation
  3. Pregnancy
    1. Expect resolution after delivery
    2. Surgical intervention is both contraindicated and unnecessary
  4. Diarrhea (Relative Risk 2.1)
  5. Obesity (Relative Risk 1.7)
  6. Family History
  7. Portal Hypertension (Cirrhosis) and Ascites
  8. Pelvic floor dysfunction
  9. Low fiber diet
  10. Anatomic abnormalities
    1. No Hemorrhoidal venous valves
    2. Intrinsic weakness of anal blood vessels
  • Symptoms (asymptomatic in >50% of patients)
  1. Pruritus Ani
  2. Rectal bleeding (often with streaks of blood on surface of stool)
  3. Rectal Pain (External Hemorrhoid, Thrombosed Hemorrhoid)
  4. Prolapsed Hemorrhoid (with risk of soiling)
  5. Fullness or mass sensation
  • Signs
  1. Visual inspection
  2. Digital Rectal Exam
  3. Anoscopy (Ives Slotted Anoscope)
    1. Required to diagnose Internal Hemorrhoids (not discernable by Digital Rectal Exam)
    2. Internal Hemorrhoids will appear as dilated purple veins
  • Exam
  1. External anal exam
    1. Observe for external hemorroids (esp. Thrombosed Hemorrhoids)
    2. Prolapsed internal hemorroids
  2. Digital Rectal Exam
    1. Rectal masses
    2. Focal tenderness or fullness
    3. Gross or Occult blood
  3. Anoscopy
    1. See Anoscopy
  • Differential Diagnosis
  1. See Colorectal Cancer Screening for guidelines irrespective of Hemorrhoids
  2. Suspected Inflammatory Bowel Disease
  3. Consider in age over 40 years and signs of rectal bleeding
    1. Positive Fecal Occult Blood Test
    2. Iron Deficiency Anemia
  4. Other red flag symptoms with rectal bleeding
    1. Abdominal Pain
    2. Weight loss
    3. Fever
    4. Rectal bleeding refractory to medical management
  • Precautions
  1. Exercise caution in diagnosing Hemorrhoids as the cause of rectal bleeding
    1. Consider proximal causes of rectal bleeding (e.g. Colorectal Cancer, Inflammatory Bowel Disease)
    2. Anemia suggests other bleeding source, as Hemorrhoids rarely bleed enough to cause significant Anemia
  • References
  1. Pickard in Dornbrand (1992) Ambulatory Care, p. 225-6
  2. Schrock in Feldman (1998) Sleisenger GI, p. 1964-7
  3. Hulme-Moir (2001) Gastroenterol Clin North Am 30:183-97 [PubMed]
  4. Hussain (1999) Prim Care 26(1):35-51 [PubMed]
  5. Mott (2018) Am Fam Physician 97(3): 172-9 [PubMed]