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Last updated: August 24, 2020
Revisions: 27

Last updated: August 24, 2020
Revisions: 27

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Haemorrhoids are defined as an abnormal swelling or enlargement of the anal vascular cushions.

Fig 1 - Haemorrhoids located in the 3, 7, and 11 o'clock positions

Figure 1 – Haemorrhoids located in the 3, 7, and 11 o’clock positions

The anal vascular cushions act to assist the anal sphincter in maintaining continence. There are three vascular cushions in the anus, positioned at the 3-, 7- and 11- o’clock positions (when looked at with the patient in the lithotomy position, i.e. anterior is 12 o’clock).

When these cushions become abnormally enlarged, they can cause symptoms and become pathological, termed haemorrhoids.

The prevalence of haemorrhoids varies, mainly due to wrong attribution of anorectal symptoms, however it is estimated that around 4% of US population complained of haemorrhoids and have a prevalence peak at age 45-65yrs.

Haemorrhoids are classified according to their size:

Classification Description
1st Degree Remain in the rectum
2nd Degree Prolapse through the anus on defecation but spontaneously reduce
3rd Degree Prolapse through the anus on defecation but require digital reduction
4th Degree Remain persistently prolapsed

Table 1 – Classification of Haemorrhoids

Risk Factors

The main risk factors for the development of haemorrhoids are excessive straining (from chronic constipation), increasing age, and raised intra-abdominal pressure (such as pregnancy, chronic cough, or ascites).

Other less common risk factors include pelvic or abdominal masses, family history, cardiac failure, or portal hypertension.

Clinical Features

Haemorrhoids typically present with painless bright red rectal bleeding, commonly after defecation and often seen either on paper or covering the pan. Importantly, blood is seen on the surface of the stool, not mixed in.

Other symptoms include pruritus (due to chronic mucus discharge and irritation), rectal fullness or an anal lump, and soiling (due to impaired continence or mucus discharge).

Large prolapsed haemorrhoids can thrombose. These are very painful and these patients frequently present acutely as an emergency patient.

Examination will usually be normal unless the haemorrhoids have prolapsed.  A thrombosed prolapsed haemorrhoid will present as a purple/blue, oedematous, tense, and tender perianal mass.

Fig 2 - Types of Haemorrhoids (A) 1st Degree Haemorrhoids, as seen on endoscopy (B) 2nd Degree Haemorrhoid (C) Thrombosis and Ulceration of External Haemorrhoid

Figure 2 – Types of Haemorrhoids (A) 1st Degree Haemorrhoids, as seen on endoscopy (B) 2nd Degree Haemorrhoid (C) Thrombosed and Ulcerated External Haemorrhoid

Differential Diagnosis

It is important to exclude other cause of rectal bleeding such as malignancy, inflammatory bowel disease, or diverticular disease.

Other perianal differentials to consider include fissure-in-ano, a perianal abscess, or fistula-in-ano. So-called “external piles” are usually just simple skin tags or “sentinel piles” from a fissure-in-ano.


Proctoscopy is typically performed to confirm the diagnosis. Any significant or prolonged bleeding or signs of anaemia would warrant a full blood count and a coagulation screen.

A flexible sigmoidoscopy or colonoscopy may also be considered to exclude malignancy in certain cases, depending on the patient’s clinical features.


Nearly all haemorrhoids can be managed conservatively, especially if asymptomatic.

Ensure to provide lifestyle advice, such as increasing daily fibre and fluid intake to avoid constipation, prescribing laxatives if necessary. Topical analgesia (such as lignocaine gel) may also be required for pain relief; avoid oral opioid analgesia as this can compound any constipation and worsen symptoms.

Often patients are not too troubled by the symptoms and simply want reassurance that the cause of the bleeding is not sinister, and often this is sufficient


Symptomatic 1st and 2nd degree haemorrhoids can be treated with rubber-band ligation (RBL)*. This involves the haemorrhoid being drawn into the end of a suction gun and a rubber band placed over the neck of the haemorrhoid. This can be done either in a clinic setting or in theatre.

*The main complications of this procedure include recurrence, pain (if the band is mistakenly placed below the dentate line), and bleeding

Fig 3 - Rubber-band ligation of haemorrhoids.

Figure 3 – Rubber-band ligation of haemorrhoids


Haemorrhoidal artery ligation (HAL) is one surgical option for 2nd or 3rd degree haemorrhoids, with equivocal effectiveness to other interventions (including RBL).

Around 5% of patients with haemorrhoids will eventually need a haemorrhoidectomy*.This is indicated if patients are symptomatic and not responding to conservative therapies, yet unsuitable for banding or injection (mainly 3rd degree and 4th degree). Typically this is either as a stapled haemorrhoidectomy or Milligan Morgan haemorrhoidectomy.

*The main complications of a haemorrhoidectomy are bleeding, infection, constipation, stricture, anal fissures, or faecal incontinence


Complications of haemorrhoids include thrombosis, ulceration or gangrene (secondary to thrombosis), skin tags, or perianal sepsis.

Key Points

  • Haemorrhoids are defined as an abnormal swelling or enlargement of the anal vascular cushions
  • There are four subtypes of haemorrhoids, classified from 1st to 4th degree
  • Haemorrhoids typically present with painless bright red bleeding
  • Haemorrhoids can be managed either conservatively or with surgical intervention if required