Haemorrhoids

Definition & Anatomy

Haemorrhoids are dilated vascular channels (cushions) between the anal mucosa and the underlying internal anal sphincter. They represent a normal part of anal anatomy; their presence only constitutes disease when symptoms arise. They occur in three consistent positions: left lateral, right posterior, and right anterior. Lesions elsewhere should raise concern for carcinoma, lymphoma, or condyloma.

Internal haemorrhoids — arise above the dentate line, covered by columnar or transitional mucosa; supplied by the superior rectal vein (portal system)
External haemorrhoids — distal to the dentate line, covered by squamous epithelium; supplied by the inferior rectal vein (systemic)

Anatomy of internal and external haemorrhoids

Cross-sectional anatomy showing internal haemorrhoids (above dentate line) and external haemorrhoids (below dentate line) — Bailey & Love's Surgery

Epidemiology

Affects approximately 10–25% of the adult population; some estimates reach 5% of the general population for symptomatic disease
Accounts for 1.9–3.5 million physician visits annually in the USA
Up to 85% of multiparous women develop haemorrhoids, though most partially regress post-delivery

Pathogenesis

Symptoms arise from loss of connective tissue support causing prolapse and susceptibility to trauma from straining or hard stool passage. Elevated circulating matrix metalloproteinases are associated with symptomatic internal haemorrhoids.

Predisposing factors:

Factor	Mechanism
Constipation / straining	↑ intra-abdominal and venous pressure
Prolonged toilet sitting	Sustained venous pressure
Low-fibre diet	Hard stool → trauma
Pregnancy	Mechanical compression of superior rectal vein + progesterone → venous stasis
Obesity	↑ intra-abdominal pressure
Portal hypertension	Dilated portosystemic collaterals

Histologically: thin-walled, dilated submucosal vessels beneath anal/rectal mucosa.

Classification of Internal Haemorrhoids

Grade	Features
I	Bleed ± enlarged; do not prolapse
II	Prolapse with defecation; reduce spontaneously
III	Prolapse; require manual reduction
IV	Remain prolapsed; irreducible

External haemorrhoids may become thrombosed (clot under squamous epithelium of the anal verge), causing acute severe pain.

Clinical Features

Internal haemorrhoids:

Painless bright red rectal bleeding — may coat the stool, drip into the toilet, or appear on tissue paper; occasionally dark blood or clots
Prolapse — feeling of a lump, mucus/blood on underwear
Pruritus ani — from perianal moisture
Pain — only if thrombosis or strangulation occurs

External haemorrhoids:

Pain is the dominant feature (squamous epithelium is exquisitely sensitive)
Thrombosed external haemorrhoid: sudden, severe perianal pain with a tender, firm, bluish lump

Important: Most patients attributing symptoms to "haemorrhoids" have a different aetiology (fissure, pruritus ani, warts, etc.). Haemorrhoids may coexist with other pathology.

Diagnosis

History and perianal inspection
Digital rectal examination
Anoscopy (beveled/slotted anoscope) — gold standard for visualising internal haemorrhoids and grading prolapse; exam may be normal between episodes
Flexible sigmoidoscopy / colonoscopy — retroflexed view in rectum; indicated to exclude proximal colorectal disease when bleeding is the presentation

Treatment

1. Conservative (Medical) — All Grades

Dietary fibre: 20–30 g/day; fibre diary to assess intake
Fluid intake: 6–8 glasses of non-alcoholic, non-caffeinated beverage daily
Avoid straining and prolonged toilet time
Stool softeners: docusate sodium; polyethylene glycol 3350 if constipation persists
Warm sitz baths: for comfort and hygiene
Topical agents: phenylephrine/mineral oil/petrolatum or glucocorticoid-based creams for temporary relief of pain/itch (caution: steroids → candidiasis with prolonged use)
Phlebotonics (e.g., diosmin/hesperidin — micronised purified flavonoid fraction): improve venous tone, stabilise capillary permeability; superior to placebo for acute symptoms; useful for grades II–III

2. Office-Based Procedures — Grades I–III (non-excisional)

Procedure	Mechanism	Notes
Rubber band ligation (RBL)	Band applied proximal to haemorrhoid → ischaemic necrosis and mucosal fixation	Most common office procedure; grade II–III; bands placed above dentate line only — distal placement causes pain
Injection sclerotherapy	Sclerosant → fibrosis and fixation
Infrared photocoagulation	Heat → coagulation and fibrosis
Bipolar/direct current electrocoagulation	Electrical coagulation
Cryotherapy	Cold-induced tissue destruction

RBL detail: Usually 1 band per session (up to 3 if local anaesthesia added); reassess at 4–6 weeks; most patients managed with ≤3 procedures. Do not apply to external haemorrhoids.

3. Surgical — Grade IV / Failed Procedures

Haemorrhoidectomy (excisional): Milligan-Morgan (open) or Ferguson (closed) — definitive treatment
Stapled haemorrhoidopexy (procedure for prolapsing haemorrhoids, PPH)
Doppler-guided haemorrhoidal artery ligation (DGHAL)

4. Thrombosed External Haemorrhoid

If seen within 72 hours of onset → surgical excision (not simple incision) for rapid relief
Beyond 72 hours or symptoms improving → conservative (sitz baths, stool softeners, analgesics)

Special Situations

Portal hypertension: Haemorrhoids represent portosystemic collaterals; bleeding can be more significant. Management is similar but with awareness of coagulopathy.

Pregnancy: Conservative management first; rubber band ligation for refractory cases. Haemorrhoidectomy if severely prolapsed, ulcerated, with bleeding, fissure, or fistula.

Differential Diagnosis

Anal fissure (posterior midline pain, tearing on defecation)
Rectal prolapse (full-thickness protrusion)
Rectal polyps / carcinoma
Condylomata acuminata
Perianal abscess
Pruritus ani
Rectal varices (portal hypertension)

Sources: Sleisenger & Fordtran's Gastrointestinal and Liver Disease, 11e; Robbins & Cotran Pathologic Basis of Disease, 10e; Clinical Gastrointestinal Endoscopy, 3e; Yamada's Textbook of Gastroenterology, 7e; Bailey & Love's Short Practice of Surgery, 28e

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