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