Haemorrhoids are abnormally enlarged vascular mucosal cushions in the anal canal. These mucosal cushions are 'normal findings' - they help to maintain anal continence. It is only when they become enlarged and start to cause symptoms that they become haemorrhoids.
Haemorrhoids originate either above the dentate line (internal haemorrhoids) or below the dentate line (external haemorrhoids). The dentate line is 2 cm above the anal verge and is the anatomical delineation between the upper and lower anal canal.
- First-degree haemorrhoids (grade I): do not prolapse.
- Second-degree haemorrhoids (grade II): prolapse on straining; reduce spontaneously.
- Third-degree haemorrhoids (grade III): prolapse on straining; can be reduced manually.
- Fourth-degree haemorrhoids (grade IV): permanently prolapsed; cannot be reduced.
They are painless unless they become strangulated. This is because the upper anal canal has no pain fibres.
- Lie under the perianal skin just inside and outside the anal verge below the dentate line.
- Are covered by squamous epithelium and have sensory innervation so may become painful and itchy.
- May be visible on external examination.
Internal and external haemorrhoids can co-exist.
Community-based studies in the UK reported that haemorrhoids affect 13-36% of the general population. However, it is likely that this estimation may be higher than the actual prevalence because the studies mainly relied on self-reporting, and many anorectal symptoms are often wrongly attributed to haemorrhoids.
Proposed factors include constipation, prolonged straining and time on the toilet, increased abdominal pressure as in ascites or during pregnancy and childbirth, heavy lifting, chronic cough, ageing and hereditary factors.
- A person may be asymptomatic.
- Bright-red, painless rectal bleeding with defecation is the most common symptom. It may be streaks on the toilet paper or blood dripping into the toilet. Blood may coat stools but is not mixed in.
- Anal itching and irritation may result from chronic mucous discharge irritating the perianal skin.
- A feeling of rectal fullness, discomfort or of incomplete evacuation on bowel movements may be present if prolapse occurs with straining.
- Prolapsed haemorrhoids may present with a history of a lump at the anal verge.
- Soiling due to mucous discharge or impaired continence may also be experienced.
- Pain is rarely felt with internal haemorrhoids unless the haemorrhoid prolapses and becomes strangulated.
- Strangulated haemorrhoids may thrombose which is intensely painful.
- External haemorrhoids do not usually cause symptoms unless thrombosis occurs causing acute severe pain and a visible/palpable perianal lump.
Signs on examination
- Non-prolapsed internal haemorrhoids are not evident on external examination and are difficult to feel on digital rectal examination.
- Local perineal irritation may be seen if chronic mucous discharge is present.
- Asking the patient to strain may allow haemorrhoids to become visible at the anal verge. They appear as bluish, bulging vessels covered by mucosa.
- Thrombosed haemorrhoids are seen as purple, swollen, acutely tender perianal lumps.
Digital rectal examination
It is essential to carry out digital rectal examination even though internal haemorrhoids will not be palpable. Other pathology needs to be excluded.
- Anal carcinoma.
- Colorectal cancer.
- Inflammatory bowel disease: Crohn's disease, ulcerative colitis.
- Rectal prolapse.
- Adenomatous polyps.
- Anal fissure.
- Condylomata acuminata (genital warts).
- Anorectal abscess.
- Anal fistula.
- Other causes of pruritus ani - eg, threadworms, contact dermatitis.
- Proctoscopy should be carried out. If facilities are not available in primary care, referral to secondary care may be needed. Haemorrhoids are seen as pink mucosal swellings.
- Even if haemorrhoids are seen on proctoscopy, this does not necessarily exclude other pathology. Refer if there is any doubt in diagnosis or if symptoms are recurrent.
- All patients with a change in bowel habit, tenesmus symptoms, abdominal pain or other lower gastrointestinal tract symptoms, should be referred for specialist opinion.
- The National Institute for Health and Care Excellence (NICE) referral guidelines for suspected cancer should be followed - see 'Further reading & references', below.
- Anal cancer may look similar to a prolapsed haemorrhoid.
- Flexible sigmoidoscopy and possible colonoscopy may be carried out to exclude other pathology.
- Anorectal physiological studies and anorectal ultrasound may be useful if there is associated soiling or incontinence.
- FBC may reveal anaemia or infection.
Treatment depends on the degree of prolapse and the severity of symptoms. Refer using the suspected cancer pathway referral (for an appointment within two weeks) if anal or colorectal cancer is suspected. Refer to an appropriate specialist if any other serious pathology, such as inflammatory bowel disease or a sexually transmitted infection, is suspected.
Prevention and management of constipation
- Increase fluid and fibre intake. Aim for an intake of 25-30 g of insoluble fibre (raw fruits, vegetables, fibre supplements) and 6-8 glasses of fluid daily. Avoid too much caffeine.
- Bulk-forming laxatives such as ispaghula husk or sterculia are preferred if constipation needs treatment. Alternatives are lactulose or sodium docusate.
Pain and symptom relief
- Simple analgesia - for example, paracetamol. Avoid constipating codeine analgesia.
- Topical therapies:
- Anaesthetic preparations may alleviate pain, burning and itching. They should be used for only a few days, as they may cause sensitisation of the anal skin.
- Topical corticosteroids may reduce inflammation and pain. Local infection must be excluded before use and they should only be used for up to seven days, as prolonged use may lead to skin atrophy, contact dermatitis and skin sensitisation.
- Good perianal hygiene may be helpful in providing symptomatic relief and preventing perineal dermatitis.
- Straining at stool should be avoided as it can make symptoms worse.
Rubber band ligation
- A band is applied to the base of the haemorrhoid which becomes necrotic after a few days and drops off.
- Up to three haemorrhoids can be banded at one time.
- A good treatment for grade II haemorrhoids with similar results to haemorrhoidectomy but without the same pain and other side-effects.
- There is a higher risk of haemorrhoid recurrence than with haemorrhoidectomy.
- Pain and haemorrhage are possible complications. The haemorrhage may be delayed (up to 5-10 days post-procedure).
Infrared energy causes tissue fibrosis which leads to mucosal fixation and a reduced chance of the haemorrhoid prolapsing.
- 5% oily phenol is injected around the base of the haemorrhoids, leading to haemorrhoid atrophy because of fibrosis of blood vessels.
- Less effective than rubber band ligation.
- Not used in large prolapsing haemorrhoids.
Bipolar diathermy; direct current electrotherapy
- The heat applied causes tissue fibrosis.
- Not so widely used.
- NICE recommends that electrotherapy can be considered as a treatment option for the treatment of grade I to III haemorrhoids.
These are reserved for large, symptomatic haemorrhoids that do not respond to other treatments.
- This is a painful procedure, performed under general anaesthesia.
- Several operative techniques have been described - eg, the Milligan-Morgan open haemorrhoidectomy.
- Excisional haemorrhoidectomy is more effective long-term than the less invasive technique of rubber band ligation, at least for grade III haemorrhoids, but at the expense of increased pain, higher complications and more time off work.
- Complications can include infection, secondary haemorrhage, urinary retention, abscess formation, faecal incontinence, fistula and anal stenosis.
Circular stapled haemorrhoidectomy
- This is a possible treatment for prolapsed, symptomatic internal haemorrhoids.
- A specialised circular stapling gun allows excision of a doughnut of mucosa from the upper anal canal. This interrupts the blood supply to the haemorrhoids and has the effect of 'pulling up' the prolapsed mucosa.
- Seems to be less painful and allow a quicker return to usual activities and work than conventional haemorrhoidectomy.
- There is a higher rate of prolapse and re-intervention for prolapse compared with conventional haemorrhoidectomy.
Haemorrhoidal artery ligation
- This involves cutting off the blood supply to the haemorrhoids, so shrinking them.
- The procedure is usually performed under general anaesthesia and a proctoscope and Doppler are used to visualise the haemorrhoidal arteries which are then sutured.
- These are extremely painful.
- Consider admission for those presenting early, as some advocate excision under local anaesthetic[1, 10]. Incision and drainage of the clot relieve pain but the thrombosis often recurs and there may be persistent bleeding.
- Conservative treatment includes analgesia, ice packs and stool softeners. A topical calcium antagonist may help to relieve pain.
- If managed conservatively, symptoms usually settle within 10-14 days.
- Skin tags can develop because of repeated haemorrhoid dilatation which causes the overlying skin to enlarge and stretch.
- Ischaemia, thrombosis and even gangrene may develop when internal haemorrhoids become strangulated.
- Perianal sepsis may occur but is rare.
- Severe or persistent bleeding may lead to anaemia.
- Thrombosed external haemorrhoids may ulcerate.
- This s generally good.
- Conservative measures are adequate for many people.
- About 10% of people will eventually need surgery.
- Haemorrhoids in pregnancy usually resolve after delivery.
- Avoidance of constipation with a high-fibre, high-fluid diet.
- Avoidance of prolonged straining.
Further reading and references
Haemorrhoids; NICE CKS, July 2016 (UK access only)
Acheson AG, Scholefield JH; Management of haemorrhoids. BMJ. 2008 Feb 16336(7640):380-3.
Suspected cancer: recognition and referral; NICE Clinical Guideline (2015 - last updated July 2017)
Brown SR, Watson A; Comments to 'Rubber band ligation versus excisional haemorrhoidectomy for haemorrhoids'. Tech Coloproctol. 2016 Sep20(9):659-61. doi: 10.1007/s10151-016-1461-3. Epub 2016 Mar 29.
Electrotherapy for the treatment of haemorrhoids; NICE Interventional Procedure Guidance, June 2015
Circular stapled haemorrhoidectomy; NICE Interventional Procedure Guidance, December 2003
Mehigan BJ, Monson JR, Hartley JE; Stapling procedure for haemorrhoids versus Milligan-Morgan haemorrhoidectomy: randomised controlled trial. Lancet. 2000 Mar 4355(9206):782-5.
Burch J, Epstein D, Sari AB, et al; Stapled haemorrhoidopexy for the treatment of haemorrhoids: a systematic review. Colorectal Dis. 2009 Mar11(3):233-43
Haemorrhoidal artery ligation; NICE Interventional Procedure Guidance, May 2010
Chan KK, Arthur JD; External haemorrhoidal thrombosis: evidence for current management. Tech Coloproctol. 2013 Feb17(1):21-5. doi: 10.1007/s10151-012-0904-8. Epub 2012 Oct 19.