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This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
The Bottom Line
- Haemorrhoids = engorged anal vascular cushions. Internal (above dentate line, painless) or external (below, painful)
- Grading: I = bleed only; II = prolapse on straining, spontaneous reduction; III = prolapse requiring manual reduction; IV = irreducible prolapse
- Painless bright red rectal bleeding (on paper/in pan, NOT mixed with stool) is the cardinal symptom
- Treatment: lifestyle/dietary measures (all grades) → rubber band ligation (grade I–II) → haemorrhoidectomy (grade III–IV)
- ALWAYS exclude proximal pathology (colorectal cancer) in patients ≥40 or with red flags — do NOT attribute bleeding solely to haemorrhoids
Overview
Haemorrhoids (piles) are engorged submucosal vascular cushions in the anal canal. Three primary cushions are located at the 3, 7, and 11 o'clock positions (in lithotomy). Internal haemorrhoids arise above the dentate line (columnar epithelium, viscerally innervated — therefore painless unless thrombosed or strangulated). External haemorrhoids arise below the dentate line (squamous epithelium, somatically innervated — therefore painful). Risk factors include straining at stool, constipation, pregnancy, obesity, prolonged sitting, heavy lifting, and chronic cough.
Epidemiology
Haemorrhoids affect approximately 50% of people at some point in their lives. Peak incidence is between ages 45 and 65. They are equally common in men and women. They are the most common cause of fresh rectal bleeding in primary care. However, it is crucial not to attribute bleeding to haemorrhoids without considering and excluding more sinister causes, particularly in older patients.
Clinical Features
Symptoms
Painless bright red rectal bleeding (on toilet paper, dripping into pan, or on surface of stool)
Perianal lump or prolapse (may require manual reduction — grade III)
Perianal itching (pruritus ani)
Mucous discharge (with prolapsing haemorrhoids)
Severe acute perianal pain (thrombosed external haemorrhoid)
Sensation of incomplete evacuation
Signs
External haemorrhoids visible on inspection
Prolapsing internal haemorrhoids visible on straining or proctoscopy
Thrombosed external haemorrhoid: tense, blue/purple, tender perianal swelling
Strangulated internal haemorrhoid: irreducible, oedematous, painful prolapse (grade IV)
Skin tags (remnants of resolved thrombosed haemorrhoids)
Investigations
First-line
ProctoscopyGold standard for diagnosing internal haemorrhoids — visualises vascular cushions above the dentate line. Can perform banding at same time
Digital rectal examinationCannot reliably feel haemorrhoids but excludes rectal mass. Essential part of assessment
Second-line
Flexible sigmoidoscopy or colonoscopyIf ≥40 years, red flags (change in bowel habit, weight loss, family history), or FIT positive — to exclude proximal colorectal pathology
FITConsider in patients with rectal bleeding + other symptoms suggestive of colorectal cancer (per NICE NG12)
1
Conservative (all grades)
- High-fibre diet and adequate fluid intake
- Stool softeners (ispaghula husk, macrogol) — avoid straining
- Topical treatments: short-term use of soothing creams/ointments (e.g. Anusol, Proctosedyl — topical corticosteroid for max 7 days)
- Avoid prolonged sitting on toilet, excessive straining, and heavy lifting
2
Office-based procedures (grade I–II)
- Rubber band ligation (RBL): most effective non-surgical treatment — application of band to base of internal haemorrhoid (above dentate line — painless area). Done at proctoscopy
- Injection sclerotherapy: 5% phenol in almond oil — alternative for grade I if banding not suitable
- Infrared coagulation: rarely used in UK
3
Surgical (grade III–IV or failed banding)
- Haemorrhoidal artery ligation (HAL/THD): Doppler-guided ligation of feeding arteries ± mucopexy
- Excisional haemorrhoidectomy (Milligan-Morgan open or Ferguson closed): definitive for grade III–IV. Most effective but most painful
- Stapled haemorrhoidopexy (PPH): alternative for circumferential prolapse — less pain, faster recovery but higher recurrence
4
Thrombosed external haemorrhoid
- If within 72 hours of onset: excision or incision under local anaesthesia (provides immediate relief)
- If >72 hours: conservative (pain is usually resolving) — analgesia, ice packs, stool softeners, topical GTN
- Will resolve spontaneously over 2–3 weeks but may leave a residual skin tag
Complications
- Thrombosed external haemorrhoid: Acute painful perianal swelling — excise if <72 hours
- Strangulated haemorrhoid: Irreducible prolapsed internal haemorrhoid — oedematous, gangrenous if untreated. Surgical emergency
- Iron deficiency anaemia: Rare from chronic haemorrhoidal bleeding — must exclude other causes before attributing to haemorrhoids
- Post-banding: Minor bleeding, pain (if band placed too low — below dentate line), rarely pelvic sepsis (very rare but life-threatening)
UKMLA Exam Tips
- 1Haemorrhoid positions: 3, 7, 11 o'clock in LITHOTOMY — corresponding to branches of the superior rectal artery
- 2Internal haemorrhoids are PAINLESS (above dentate line, visceral innervation) unless thrombosed or strangulated
- 3NEVER attribute rectal bleeding to haemorrhoids without excluding proximal colorectal pathology — especially in patients ≥40
- 4Rubber band ligation is applied ABOVE the dentate line (painless area) — banding below = severe pain
- 5Grading system: I = bleed, II = prolapse + spontaneous reduction, III = requires manual reduction, IV = irreducible
- 6Thrombosed external haemorrhoid <72 hours = excise. >72 hours = conservative (resolving naturally)
practicetest your knowledge on haemorrhoidsApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — gastroenterology and beyond.
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