Anal Fissure


An anal fissure is a break or tear in the skin of the anal canal. Most acute anal fissures heal within 1-2 weeks with laxatives and barrier creams. Chronic anal fissures are defined as persisting tears not healing within 6 week and may require use of an anal dilatation cream (rectal GTN 0.4% ointment).  Primary anal fissures are described as those with no clear underlying causes, whereas secondary anal fissures are those with a clear underlying cause.  Constipation is the most common cause of anal fissures, but it can also be caused by inflammatory bowel disease, certain STIs, colorectal cancer, trauma, certain drugs, and childbirth

The incidence is around 1 in 350 people and are more common in people aged 15–40 years but can occur at any age.  Primary anal fissures are uncommon in elderly people.  Acute anal fissures are significantly more common than chronic anal fissures



  1. Ask about symptoms:
    1. Anal pain always occurs with defecation. Pain is severe and sharp on passing a stool, commonly followed by deep burning pain that persists for several hours afterwards
    2. Bleeding may occur with defecation. When present, it is usually seen as a small quantity of bright red blood on the stool or toilet paper
    3. Anal spasm and a tearing sensation on passing stool are also commonly reported
  2. Ask about the duration of symptoms:
    1. Acute anal fissures are present for less than 6 weeks
    2. Chronic anal fissures are present for 6 weeks or longer
  3. Ask about features of an underlying cause, including:
    1. Dietary and bowel habits (including whether there is constipation, diarrhoea, or any recent changes)
    2. Previous anorectal trauma (including anal surgery and obstetric history)
    3. Associated symptoms (such as abdominal pain or weight loss)
    4. Family history of possible underlying causes (such as colorectal cancer or inflammatory bowel disease)



  1. Assess the anal fissure:
    1. Acute anal fissures are superficial with well-demarcated edges
    2. Chronic anal fissures are wider and deeper with muscle fibres visible in the base. The edges are often swollen, and a skin tag may be visible at the end of the fissure
    3. Primary anal fissures are usually singular and occur in the posterior midline of the anus, although a few cases may be seen in the anterior midline (especially in women)
    4. Secondary anal fissures may have an irregular outline, be multiple, or occur laterally
    5. Anal spasm and pain may prevent full visualization of the fissure. When the fissure cannot be seen, pain occurs with gentle pressure on the anal margin
  2. Exclude a thrombosed haemorrhoid, which may present similarly
  3. If a secondary anal fissure is suspected, assess for features of an underlying cause, such as:
    1. Constipation — see Constipation and Constipation in Children  for more information
    2. Colorectal cancer
    3. A sexually transmitted infection (such as HIV infection and AIDS, and syphilis)
    4. Inflammatory bowel disease — see Crohn's disease and Ulcerative colitis for more information


Although rare, suspect sexual abuse if a child has an anal fissure and possible causes (such as constipation, Crohn's disease, and passing hard stools) have been excluded

NOTE A digital rectal examination is not recommended in primary care to diagnose anal fissure

Consider referral for examination under anaesthesia if the diagnosis is unclear or if spasm and pain make diagnosis impossible


Exclude Red Flag Symptoms

Refer (using clinical judgement to determine the urgency) if a serious underlying cause is suspected:

  • rectal cancer
  • inflammatory bowel disease
  • a sexually transmitted infection (such as HIV infection and AIDS)


Consider referring to a general or colorectal surgeon if anal fissure occurs in an elderly person


Initial management

For people with secondary anal fissure for whom referral is not indicated:

  1. Manage the underlying cause, where possible
  2. Advise the person to increase the amount of fibre in their diet and increase their fluid intake to ensure stools are soft and easy to pass
  3. Offer pain relief (either paracetamol or ibuprofen) if there is prolonged burning pain following defecation
  4. For an adult with extreme pain on defecation, consider prescribing a short course (a few days) of a topical anaesthetic (lidocaine 5% ointment) for use before passing a stool
  5. For an adult with a primary anal fissure who has had symptoms for 1 week or more without improvement, consider prescribing rectal glyceryl trinitrate (GTN) 0.4% ointment
  6. Give lifestyle advice to aid healing of the anal fissure such as advice on the importance of correct anal hygiene, especially in children, and advise against 'stool withholding' and undue straining during bowel movements
  7. Advise parents/carers of a child with a primary anal fissure to return if the fissure is unhealed after 2 weeks, or earlier if the child is still in a lot of pain
  8. Review adults with a primary anal fissure if the fissure is unhealed after 6–8 weeks, or earlier if necessary (for example if the person develops intolerable adverse effects from rectal GTN ointment)
  9. Follow up with patients with secondary anal fissures with a frequency based on the underlying cause
  10. Advise a person with a primary anal fissure that when the fissure has healed, they should continue with the dietary and lifestyle measures to reduce the risk of recurrence


Management and referral for unhealthy or recurrent anal fissures

If the anal fissure is unhealed:

  1. In a child after 2 weeks (or earlier if the child is still in a lot of pain):
    1. Seek specialist advice or refer to a paediatrician or a paediatric surgeon
  2. In an adult after 6–8 weeks but the person is asymptomatic or has notable symptomatic improvement, either:
    1. Prescribe a second course of rectal glyceryl trinitrate (GTN) 0.4% ointment and review the person after a further 6–8 weeks, or
    2. Refer the person to a general or colorectal surgeon
  3. In an adult after 6–8 weeks and there is no notable symptomatic improvement:
    1. Confirm that rectal GTN ointment was used for 6–8 weeks
    2. If there was inadequate adherence to treatment, seek specialist advice about prescribing topical diltiazem 2%
    3. If there was adequate adherence to initial treatment, refer the person to a general or colorectal surgeon


If anal fissure recurs after the initial episode has healed:

  1. Enquire about continuation with dietary and lifestyle measures
    1. If there was inadequate adherence, reinforce the importance of doing so, and manage the anal fissure
    2. If there was adequate adherence, refer the person to a general or colorectal surgeon for investigation and consideration of more intensive treatment


Also refer:

  • Anal fissures that are multiple, off the midline, large, or irregular (atypical fissures) as these may be the manifestation of underlying disease (e.g. Crohn’s disease, ulcerative colitis, anal herpes, syphilis, Chlamydia, gonorrhoea, AIDS, tuberculosis, or neoplasm)


NOTE:  Anal skin tags are not commissioned for excision


Advice and Guidance is being made available for all specialties, and is being provided by consultant specialists at East Kent Hospitals.  To make a request or to check to if a query has been answered, you will need to log in via the electronic Referral System (eRS)

Click here for the "how to access" e-Referral Advice and Guidance Manual for instructions on how to make a request and check responses

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