This is swelling and inflammation of the veins in the rectum and anus. They are THE most common cause of rectal bleeding. They are extremely common in adults.


  • Associated with constipation (it is thought haemorrhoids can develop as a result of straining)
  • Often develop for the first time during pregnancy.
  • Caused by congestion of the internal and/or external venous plexuses in the anal region.

Clinical Features

  • Bleeding – the blood will be bright red
  • Discomfort
  • Pruritus ani – this is irritation of the skin around the anus, and usually causes the desire to scratch. It has many causes.
  • Mucus discharge
  • They may produce blood on the toilet paper and blood on the outside of the stools.


There are three types of haemorrhoid:
  • Primary (internal ) – these may cause bleeding, but are not visible from the outside
  • Second degree (prolapsing) – these can also bleed, and may ‘pop out’, but they can retract (and prolapse again) spontaneously.
  • Third degree (prolapsed) – these require manual replacement after they have prolapsed.


  • Primarily involves measures to prevent constipation and straining. 

More invasive techniques include:

  • Sclerotherapy – this is where there is an injection into a vein that causes it to dramatically shrink. It can also be used on lymphatic drainage vessels. It is a common procedure to treat haemorrhoids and varicose veins in adults. The vein is injected with a sclerosing agent, which will make the vein immediately shrink. Over the next few weeks, the vein tissue will be absorbed by the body.
    • This is particularly effective for treating vein problems because it also helps to sclerose feeder veins, and this prevents recurrence of the problem. It is often the preferred treatment for small varicose veins and haemorrhoids.
  • Band ligation – a small band is tied round the vessel and this restricts the blood flow, and the vessel will be absorbed (as seen in treatment of oesophageal varices).
  • Haemorrhoidectomy is also sometimes performed. This is usually curative.

Anal Fissures

  • This is a tear in the skin that lines the anus below the level of the dentate line. It will be painful on defecation.
  • It can be a primary problem in young to middle-aged adults, but also is associated with Crohn’s and UC.
  • They most commonly occur in the midline posteriorly.
  • An oedemomatous skin tag is common next to the lesion. This is sometimes called a sentinel pile.
  • The fissures can often be seen externally, but examination is difficult due to pain and sphincter spasm. Sphincter spasm may also impair wound healing.
  • Treatment usually involves an anaesthetic cream and a stool softener. Nitric oxide may also be given to aid relaxation of the internal sphincter.

Fistula in ano

  • These most commonly result from infection of anal glands by normal colonic bacteria. They also occur in Crohn’s disease.
  • They usually present as abscesses and heal once the abscess is excised.
  • Management is usually surgical – 90% of fistulas are managed in this way.

Anorectal abscesses

  • These are 3x as common in men as women. They are particularly common in gay men who indulge in penetrative anal sex.
  • They are a common cause of admission to hospital.
  • They are often the first manifestation of Crohn’s, UC and TB.
  • They will present with painful tender swellings and discharge.
  • They are surgically excised and drained, and follow up treatment is with antibiotics. Before this takes place they are sometimes imaged with MRI, perhaps also with local anaesthetic and ultrasound.

Rectal pro​lapse, intussusception and solitary rectal ulcer syndrome (SRUS)

  • All these conditions are thought to be interrelated, with the underlying cause thought most commonly to be rectal prolapse.
  • Rectal prolapse is basically where the walls of the rectum will protrude through the opening of anus and become visible. Normally, rectal prolapse starts out as an intussusceptionthis is where part of the intestine slides into another part, in the way parts of a telescope slide into eachother. Gradually this intussusception gets bigger and bigger until eventually, it prolapses out of the anus. Constipation and chronic straining are a likely cause. However, in addition to this, the presence of an intussusception in the rectum will lead to a feeling of a stool in the rectum (tenesmus), and will mean that the patient will feel the need to defecate.
    • In some patients, repeated straining will lead to the formation of a SRUS, usually on the anterior wall of the rectum. SRUS is not as simple as it sounds. It causes local inflammatory changes that appear non-specific on histological examination. It may also be difficult to distinguish from cancer on endoscopic examination.
  • Patients usually present with slight bleeding and the presence of mucus on defecation. There may also be tenesmus and a feeling of incomplete defecation.
  • Asymptomatic SRUS should not be treated. Otherwise, patients should be advised not to strain, and should take stool softeners.
  • If rectal prolapse can be demonstrated on defecation, then this may need to be treated surgically.

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