Intended for healthcare professionals

Practice 10-Minute Consultation

Chronic anal fissure in adults

BMJ 2022; 376 doi: (Published 12 January 2022) Cite this as: BMJ 2022;376:e066834
  1. Artaza Gilani, general practitioner in north west London; honorary lecturer1,
  2. Gillian Tierney, consultant general and colorectal surgeon; honorary professor2
  1. 1UCL Research Department of Primary Care and Population Health, University College London Medical School (Royal Free Hospital Campus), London NW3 2PF, UK
  2. 2Royal Derby Hospital, Derby DE22 3NE, UK; University of Nottingham, Nottingham NG7 2RD, UK
  1. Correspondence to: Artaza Gilani artaza.gilani{at}
  • Accepted 26 November 2021

What you need to know

  • Anal fissure generally causes extreme pain that may be debilitating—severe, sharp pain during defecation and significant post-defecation pain

  • Less common causes (such as inflammatory bowel disease and malignancy) need to be considered, especially if the fissure is irregular, recurrent, multiple, persistent or non-healing, or located laterally

  • Most primary fissures heal with lifestyle and pharmacological (topical glyceryl trinitrate or diltiazem) measures. Botulinum toxin and surgical options may be explored in secondary care

An otherwise healthy 24 year old schoolteacher presents with a three month history of sharp, severe anal pain on defecation. There is bright red blood on wiping and an intense burning pain that persists for several hours after bowel movements. He is on sick leave because the pain is so extreme.

An anal fissure is a tear in the skin of the anal canal.1 Anal fissures are common, particularly in middle aged adults, children, and infants.2 There is no consensus on the timeframe that makes a fissure chronic, but most sources consider the cut-off to range from four to 12 weeks.3 Presentation to primary care is commonly delayed due to embarrassment, despite the often highly distressing symptoms. Topical treatments can be effective, although side effects are common. This article outlines a primary care consultation with an adult presenting with symptoms of a chronic anal fissure.

How this article was created

We searched Medline and the Cochrane Library using the terms “anal fissure” “anal fissure diagnosis” “anal fissure treatment” and “anal fissure management.” Formal guidelines from the National Institute for Health and Care Excellence (NICE) on anal fissure have not been published, but there is a Clinical Knowledge Summary (CKS) topic on anal fissure, which we used for reference. We also made use of UpToDate and BMJ Best Practice.

What you should cover


Symptoms of painful defecation and rectal bleeding are strongly suggestive of an anal fissure. Conditions may coexist—for example, haemorrhoids and anal fissure. The patient’s history should be broad enough to account for this. Many differentials share similar presenting features (box 1). Key to diagnosis is the nature of pain (with or without bleeding) and its relationship to defecation.

Box 1

Common causes of perianal symptoms*

  • Anal fissure—Pain on defecation likened to passing broken glass, and bright red bleeding is seen on wiping (compare with haemorrhoids, which, in contrast to fissure, typically cause painless, rather than painful, rectal bleeding on defecation). Symptoms of a fissure may wax and wane.

  • Haemorrhoids—Typically painless bright red bleeding on defecation, perianal itch, and occasional prolapse. Pain, dull in nature, is an uncommon feature and usually seen with thrombosis or strangulation.

  • Anal abscess—A tender perianal lump with dull, throbbing pain which may be associated with systemic symptoms such as fever. Blood, mixed with pus may be seen if the abscess bursts

  • Anal fistula—Sometimes follows an anal abscess and usually presents with bloody/purulent discharge, perianal itch, and discomfort. Patients may report a damp patch in their underwear

  • Anal cancer—May present with a tender ulcerated or non-ulcerated mass with pain, bleeding, and weight loss. Can be an incidental finding on inspection

  • Rectal cancer—May present with change in bowel habit, urgency, bleeding, and tenesmus, as well as other red flag symptoms, including unintentional weight loss

  • Proctitis—May present with blood mixed with stool, urgency, and perianal discomfort. Other systemic features of inflammatory bowel disease may be present

  • Functional —This complex group of conditions may present with bleeding and anal pain. Examples include

    • Levator ani syndrome (regular, long lasting aching or pressure in the rectum, worsened by sitting and relieved by walking)

    • Solitary rectal ulcer syndrome (a misnomer for an uncommon condition in which ulcers are not always present and has broad and varied symptoms, including pain, rectal bleeding, and a sense of incomplete evacuation)

    • Proctalgia fugax (recurrent sudden, severe cramping rectal pain which often occurs at night)

  • Sexually transmitted infection—May present with anal pain and bleeding in combination with other genitourinary symptoms such as urethral discharge

  • * The list is not prescriptive because symptoms are not always present or absent in all cases, and conditions can coexist or present atypically

  • Is defecation painful? Pain from a fissure is typically severe and sharp (common descriptions include knife-like, passing broken glass, tearing, or splitting). A burning pain may persist for several hours after defecation.

  • Is there rectal bleeding? Bright red blood on wiping or on the surface of the stool often occurs with a fissure.1 Other types of bleeding, such as darker blood or blood mixed with the stool, may indicate a more proximal cause (such as colitis or cancer). Some patients (such as those who require help with personal care or who have a visual impairment) may be unaware of bleeding, and a collateral history may be useful.

  • How long have symptoms been present? Most acute fissures heal within one to two weeks.4 There is no consensus on how long a fissure needs to be present to be classified as “chronic,” but most cut-offs range from four to 12 weeks.3

  • Is there incontinence? Continence is not usually affected. Establish baseline continence to guide future management options.

  • Has this happened before? This may help identify patients who could be offered referral for recurrent anal fissure, which may be a sign of an underlying condition such as inflammatory bowel disease.

  • What impact have symptoms had on day-to-day life? Quality of life and mental health may be affected.5 Fearful of pain, patients may avoid opening their bowels, predisposing to constipation, and forming a vicious cycle. Pain may make it difficult to work, exercise, socialise, or even sit.

Consider underlying causes (box 2). Ask about unintentional weight loss, a change in bowel habit, tenesmus, loss of appetite, abdominal pain, fevers, night sweats, rashes, and family and sexual history. Primary causes are usually the result of local trauma (including constipation) rather than an underlying medical condition. Secondary causes are less common and tend to improve as the underlying medical condition improves.

Box 2

Common causes of anal fissure6*

Primary causes

  • Constipation†

  • Diarrhoea†

  • Vaginal delivery

  • Anal trauma

  • Anal surgery

Secondary causes

  • Inflammatory bowel disease—Anal fissures are more common in Crohn’s disease than ulcerative colitis7

  • Granulomatous diseases—Such as extrapulmonary tuberculosis, sarcoidosis

  • Malignancy—Such as squamous cell anal cancer, leukaemia

  • Communicable diseases—Such as HIV infection, syphilis, chlamydia

  • *In additional to the factors listed, primary fissures may also have no clear underlying cause

  • †Consider the underlying cause of these



Explain to the patient that their symptoms may be due to an anal fissure—a tear at the edge of the anus—and that examination can help confirm this. Seek consent and offer a chaperone. During the initial assessment, inspect the perianal area. If there are no red flags and symptoms are typical of a fissure, we recommend deferring digital rectal examination (to exclude other serious anorectal conditions) to a follow-up appointment when the patient’s pain has improved.

  • An acute fissure appears as a superficial laceration with well demarcated edges (like a paper cut).

  • Chronic fissures are wider and deeper than acute fissures, and have raised edges that may be swollen. Sphincter muscle fibres may be visible at the base of a chronic fissure. At the proximal end of a chronic anal fissure may be hypertrophied anal papillae, while at the distal margin may be a skin tag (sentinel pile).

  • Primary, or typical, fissures are usually singular. They generally occur in the posterior midline; they occur less commonly in the anterior midline, but more so in women.13 Atypical fissures (multiple, laterally located. or with irregular borders) may indicate a secondary cause (fig 1).

  • A fissure isn’t always visible and does not need to be seen for diagnosis to be made. For instance, anal spasm and/or pain may make it difficult to visualise the fissure. Asking the patient to strain can sometimes reveal the fissure. Gentle pressure on the anal margin may produce pain.

Fig 1
Fig 1

Diagram showing different locations (anterior, posterior, or lateral) and types of fissure (such as irregular, multiple, lateral). Primary or typical fissures are usually singular and tend to occur in the posterior midline (less commonly in the anterior midline). Laterally located fissures or those that are irregular or multiple regardless of location tend to be secondary

What you should do

For patients with a chronic anal fissure who are unlikely to have a secondary cause, explain what an anal fissure is and how they come about. We explain a fissure is a tear in the lining of the anus, that the underlying cause is usually unclear, but may be related to local trauma caused by constipation or diarrhoea, although in many cases neither of these are present. We emphasise the vicious circle of pain and spasm, which prevent healing. Hence, the aims of treatment are to relieve spasm and improve blood supply to the fissure, which should help alleviate symptoms and heal the fissure.

Dietary and lifestyle changes

These should continue long term. Stool should be soft, passed easily and without straining. Suggest minimising delay between getting the urge to defecate and going to the toilet. Not more time than is needed should be spent on the toilet. Recommend regular exercise (150 minutes of moderate intensity activity per week), weight management (if relevant), good hydration and a balanced diet, including adequate dietary fibre (~30 g a day for adults8). Highlight that soluble fibre is good for constipation, but fibre in general also reduces risk of a range of illnesses, including cardiovascular disease, type 2 diabetes, and colorectal and breast cancer.9 Increase fibre intake gradually to avoid flatulence and bloating.

Sitting in a warm, shallow bath that bathes the perineum (sitz bath) is often recommended, but evidence is weak.1011 Other measures such as bidets, or therapeutic local heat application may be more practical, but data for these measures are lacking.

Pharmacological management

A topical anaesthetic (such as lidocaine ointment) applied externally to the anal area may relieve pain on defecation. It may take 30 minutes to work. Avoid long term use. Suggest regular paracetamol and/or ibuprofen for post-defecatory pain. Avoid opioids (such as codeine and tramadol) as they cause constipation, unless pain cannot be managed with the aforementioned measures.

Topical glyceryl trinitrate (GTN) and diltiazem promote healing of anal fissures (through vasodilatation and improving blood supply to the fissure) and are analgesic, although fissure recurrence may occur. In the UK, 0.4% GTN is licensed for relief of pain associated with chronic fissure, whereas diltiazem is currently unlicensed. Evidence of comparative efficacy is limited, but, when used for chronic anal fissure, they are considered equally effective, with initial efficacy approximately 70%.12

The Association of Coloproctology of Great Britain and Ireland and the American Society of Colon and Rectal Surgeons currently recommend topical diltiazem as the first line pharmacological agent for chronic fissure.1314 Conversely, the NICE commissioned Clinical Knowledge Summary suggests GTN 0.4% ointment as first line treatment in adults who have had symptoms of a primary anal fissure for ≥1 week without improvement.15 GTN commonly causes headache, so we recommend taking paracetamol before applying it, and applying it with clingfilm wrapped around the finger to reduce systemic absorption, and, therefore, risk of headache.

Diltiazem may cause perianal itch, dermatitis, and headache, but headache is 85% less likely to occur with diltiazem than GTN, so diltiazem may be better tolerated.1216 Topical diltiazem should be kept refrigerated and used within four weeks of opening (so prescribe two tubes per treatment course), whereas topical GTN needs to be used within eight weeks. Advise patients to complete the 6-8 weeks treatment course even if symptoms resolve before then.


We recommend reviewing all patients with anal fissure no later than 6-8 weeks after start of treatment. This is to ensure that symptoms have resolved and to re-examine the perianal area and conduct a digital rectal examination (especially if this was not done at the first visit) to help confirm that the fissure has resolved and to assess for any coexisting anorectal pathology.

Investigations and when to refer

Consider referral for elderly patients (in whom primary fissures are uncommon and there is higher chance of malignant causes); patients with non-healing or recurrent fissures, atypical features (lateral location, irregular margins, multiple fissures), or red flags; and patients who have tried topical treatment for 6-8 weeks without adequate response.

Investigations in secondary care depend on the clinical scenario but may include colonoscopy, flexible sigmoidoscopy, examination under anaesthesia, biopsy, and culture. If primary fissure is confirmed, botulinum toxin injection may be offered. The operative management of anal fissure is reviewed elsewhere.1718

Education into practice

  • Do you have local prescribing guidelines about topical treatments for anal fissure?

  • How could you optimise the care of patients with anal fissure who are awaiting secondary care review?

How patients were involved in the creation of this article

The article was discussed with a patient, who commented that they wished they had known that a topical treatment for fissures was available that did not cause a headache as a side effect. The topical treatment least likely to cause headache is discussed further in the pharmacological measures section of the article.


We thank general practitioners Kiran Pitrola and Alison Rackham for commenting on the relevance and applicability of the contents of the article to primary care.


  • This is part of a series of occasional articles on common problems in primary care. The BMJ welcomes contributions from GPs.

  • Contributors: AG had the idea for the article, conducted the literature search, and wrote the first draft of the article. All authors then reviewed and revised the content. All authors approved the final version to be published. GT was the contact for patient involvement and conceptualised box 1. AG is the guarantor.

  • Competing interests: We have read and understood BMJ policy on declaration of interests and have no relevant interests to declare.

  • Provenance and peer review: Commissioned; externally peer reviewed.


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