Colorectal Surgery

Haemorrhoids

Haemorrhoids are symptomatic anal cushions causing bleeding, prolapse, itching or pain; do not assume rectal bleeding is haemorrhoidal without appropriate examination and cancer-pathway judgement.

Definition

Haemorrhoids are enlarged or symptomatic anal vascular cushions. Internal haemorrhoids arise above the dentate line and are graded by prolapse; external haemorrhoids arise below it and may thrombose.

Epidemiology

Haemorrhoidal symptoms are common and associated with constipation, straining, pregnancy, prolonged sitting and increasing age. Rectal bleeding remains a symptom requiring context-based assessment rather than automatic attribution.

Pathophysiology

Sliding of anal cushion tissue, venous congestion and weakening supporting tissue cause enlargement and prolapse. Thrombosis produces acute inflammation and pain in external disease.

First principles

The anal cushions are normal anatomy until symptomatic

Haemorrhoidal cushions contribute to continence. Symptoms arise when vascular tissue enlarges, prolapses or thromboses; internal haemorrhoids are above the dentate line and external disease is below it.^1,2

Prolapse and bleeding are different from thrombosis

Internal haemorrhoids commonly cause painless bright-red bleeding and prolapse graded I to IV. Thrombosed external haemorrhoids cause an acutely painful bluish lump; severe pain, fever or spreading inflammation suggests another urgent diagnosis.^1,3

Presentation

Typical symptoms include painless bright-red bleeding, prolapse, mucus, itching, soiling or a palpable lump. Pain is more suggestive of thrombosis, strangulation, fissure or abscess than uncomplicated internal haemorrhoids.^1,3

Cardinal features

Bright-red bleeding after defecation
Prolapse with or without spontaneous reduction
Itching, mucus, soiling or difficulty cleaning
Acute tender blue perianal lump in external thrombosis
Constipation, straining or prolonged toilet sitting

Red flags

Persistent or unexplained rectal bleeding, iron-deficiency anaemia, weight loss or change in bowel habit
A mass, altered stool calibre, family history or age-related colorectal-cancer concern
Severe constant pain, fever, urinary retention, spreading erythema or pus
Atypical ulceration, immunosuppression or failure to improve with appropriate treatment

Investigations

History and perianal inspection

Characterise bleeding, prolapse, pain, bowel habit, duration, medications, pregnancy, family history and cancer symptoms. Inspect for internal prolapse, external thrombosis, fissure, abscess, skin disease and masses.

Expected finding: Typical internal haemorrhoidal prolapse or external thrombosis with no red flags; atypical findings change the pathway.

^1,3

Digital rectal examination

Assess the anal canal and rectum for masses, tenderness, blood and sphincter tone when pain permits. A normal DRE does not exclude proximal pathology or replace indicated endoscopy.

Expected finding: Haemorrhoids may be palpable only when prolapsed; a mass or unexplained blood needs further assessment.

^1,2

Anoscopy or proctoscopy

Use when internal haemorrhoids need confirmation or office treatment is being planned. Avoid forcing instrumentation in severe acute pain and arrange specialist examination when necessary.

Expected finding: Internal cushions, bleeding point, prolapse grade or another anorectal lesion.

^1,2

Investigate rectal bleeding appropriately

Use FBC and colorectal investigation according to bleeding pattern, age, anaemia, weight loss, bowel-habit change, family history and national suspected-cancer guidance. Do not attribute all bleeding to haemorrhoids.

Expected finding: Anaemia, proximal colorectal disease or another cause of bleeding may coexist with haemorrhoids.

^1,3

Management

Step	Detail	Source
Correct stool and toilet factors	Increase fibre and fluid where appropriate, treat constipation with a suitable laxative, avoid straining and prolonged toilet sitting, and maintain gentle hygiene. This is first-line for bleeding, prolapse and irritation.^1,3	NICE CKS and NHS haemorrhoid information
Use short-term symptom treatment carefully	Use simple analgesia and, when appropriate, short-term topical preparations for itch or pain. Review the product ingredients and BNF cautions; prolonged topical corticosteroid or local-anaesthetic use can irritate or sensitise skin and does not correct prolapse (see BNF/local protocol for medicines).^1,4,5	NICE CKS and BNF topical medicine monographs
Offer office treatment for persistent internal haemorrhoids	For symptoms persisting despite conservative treatment, colorectal or trained specialist services may offer rubber-band ligation, injection sclerotherapy or other appropriate office treatment according to grade, anatomy and local expertise. Explain bleeding, pain and recurrence risks.^2,1	ACPGBI/ESCP haemorrhoidal-disease guideline
Refer advanced or refractory prolapse for surgery	Persistent grade III or grade IV prolapse, recurrent symptoms or failure of office treatment may require haemorrhoidectomy, stapled procedures or haemorrhoidal artery ligation in selected patients. Discuss recurrence, postoperative pain, bleeding and continence risks, and choose the procedure through colorectal services.^2,6	ACPGBI/ESCP guideline and NICE HTG218
Manage acute external thrombosis and strangulation urgently	Provide analgesia and urgent colorectal assessment for a severely painful thrombosed external haemorrhoid, strangulated prolapse or uncertain diagnosis. Procedural excision is patient- and timing-dependent; do not apply a rigid time cut-off without specialist assessment. Fever, pus or systemic illness needs an abscess/sepsis pathway.^1,2,3	NICE CKS, ACPGBI/ESCP guideline and NHS information
Follow up bleeding and recurrence	Review symptom response, bleeding, prolapse, bowel habit and treatment adverse effects. Escalate persistent bleeding, anaemia, weight loss, change in bowel habit, mass, severe pain or failure to heal; reinforce stool regulation after improvement.^1,3	NICE CKS and NHS haemorrhoid information

Illustrations

Anatomy of the anal cushionsDiagram of the anal canal showing the vascular cushions at 3, 7 and 11 o'clock above the dentate line, and the sensory transition below it.PassFinals · original

Thrombosed external haemorrhoidClinical photograph of a tender, bluish perianal swelling representing an acutely thrombosed external haemorrhoid.Braegel Home, Wikimedia Commons · CC-BY-3.0

Differentials

Anal fissure

Severe pain during/after defecation with a linear tear; uncomplicated internal haemorrhoids are usually painless.

Colorectal cancer or polyp

Persistent bleeding, anaemia, weight loss, change in bowel habit, altered stool calibre or mass.

Perianal abscess

Constant throbbing pain, fever, swelling or pus; urgent drainage pathway.

Rectal prolapse

Full-thickness circumferential prolapse with concentric folds rather than radial haemorrhoidal columns.

Inflammatory bowel disease

Diarrhoea, abdominal symptoms, weight loss, perianal disease or atypical multiple lesions.

Complications

Bleeding and iron-deficiency anaemia
Thrombosis or strangulation
Ulceration and infection
Recurrent prolapse
Postoperative pain, bleeding or continence disturbance

Prognosis

Many symptoms improve with stool regulation. Persistent, recurrent or advanced prolapse may need office treatment or surgery; recurrence and procedure-related complications should be discussed.

Guidelines

Haemorrhoids (NICE CKS, 2025)
Guideline for haemorrhoidal disease (ACPGBI/ESCP, 2020)
Haemorrhoidal artery ligation (HTG218) (NICE, 2010)

References

Evidence checked: 2026-08-03

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.