Anorectal disease: haemorrhoids, fissure and fistula

• Haemorrhoids, anal fissure, perianal abscess and fistula-in-ano are the common benign anorectal disorders: painful, often recurrent, and frequently confused with one another and with anal cancer.
• Haemorrhoids are enlarged vascular cushions, classified by prolapse (Goligher grades I to IV); first-line care is conservative, with rubber band ligation the most effective office treatment and excisional haemorrhoidectomy for advanced or combined disease.
• A primary anal fissure is a posterior midline tear driven by internal sphincter hypertonicity and ischaemia; acute fissures usually heal with fibre, sitz baths and analgesia, while chronic fissures may need topical nitrate or calcium channel blocker, botulinum toxin or lateral sphincterotomy.
• A perianal abscess is treated promptly with incision and drainage; one-half to two-thirds of patients already have, or later develop, a fistula-in-ano, which is classified by its relation to the sphincters (Parks).
• In the UK, red flags for anal cancer are an unexplained anal mass or unexplained anal ulceration; any lateral, multiple, non-healing or atypical fissure, and any mass, also needs referral.
• Faecal incontinence is common, especially in women and older adults, and usually starts with conservative bowel management before surgical referral.
• Pruritus ani is usually secondary (haemorrhoids, fissure, infection, dermatitis); persistent or long-standing idiopathic pruritus in a patient over 50 should prompt exclusion of neoplasia.

By the end of this page you should be able to:

1. Classify haemorrhoids by Goligher grade and match each grade to the appropriate step in management.
2. Explain why a primary anal fissure occurs in the posterior midline and how its acute and chronic forms differ.
3. Drain and manage a perianal abscess safely, and classify a fistula-in-ano by the Parks system.
4. Apply Goodsall's rule when planning fistula surgery.
5. Recognise atypical anorectal features that require investigation for cancer or inflammatory bowel disease.
6. Outline assessment and first-line management of faecal incontinence and pruritus ani.

The anorectal conditions below share the same territory but are different diseases. The dentate line (pectinate line) is the boundary between columnar rectal mucosa above and squamous anoderm below; it marks where visceral and somatic innervation change.

Internal haemorrhoids are graded by prolapse (Goligher), because the grade predicts treatment.

The Parks classification is the standard way surgeons describe fistula anatomy, because it predicts continence risk.^[3]

Haemorrhoidal disease is one of the commonest medical and surgical disorders in industrialised countries, accounting for more than 2.2 million outpatient evaluations a year in the United States.^[1] Reported symptomatic prevalence is of the order of 4% of adults, but higher figures appear in screening populations, so published estimates vary.^[1]

Anal fissure has no reliable population incidence, but it is one of the commonest benign anorectal conditions seen in primary and surgical practice.^[2] Peak incidence is in people aged 15 to 40 years, although fissure can occur at any age.^[2]

Perianal abscess is more common in men than women, and although it can occur at any age, its peak incidence is in people aged 20 to 40 years.^[3] Around one-half to two-thirds of patients with an abscess either have, or later develop, a fistula-in-ano: 30% to 70% present with a concomitant fistula, and of those who do not, 30% to 50% are diagnosed with a fistula months to years later.^[3]

Pruritus ani appears in 1% to 5% of the population, is more common in men than women (ratio about 4:1), and peaks in people aged 40 to 60 years.^[6]

Faecal incontinence is common but often concealed. Prevalence ranges from 1.4% to 18% in women, depending on definition and setting, with an incidence of about 12.5% in a primary care network; rates in nursing homes may reach 50%.^[4] Faecal incontinence is the second leading cause of nursing home placement in the United States.^[4]

Haemorrhoids. Constipation and abnormal bowel habits (straining, prolonged sitting, frequent bowel movements) play a major part: in a systematic review of 17 case-control and 2 cohort studies, patients with haemorrhoids had a significantly higher prevalence of constipation than controls (odds ratio 2.09; 95% confidence interval 1.27 to 3.44).^[1] Other associations are chronic diarrhoea, pregnancy, pelvic floor weakness, low fibre intake and age. There is no known single cause in a given patient.

Anal fissure. Fissure usually follows trauma and irritation, often precipitated by constipation or diarrhoea, producing a tear that fails to heal because the internal sphincter becomes hypertonic and the anoderm ischaemic.^[2] Patients with symptoms lasting more than one year are less likely to respond to medical therapy.^[2]

Perianal abscess and fistula-in-ano. Most arise cryptoglandularly from obstruction of an anal gland. An abscess and fistula can also be manifestations of Crohn disease, in which 10% to 20% of patients in population studies and 50% in longitudinal studies develop fistula-in-ano, and nearly 80% of those seen at tertiary centres have a history of fistula-in-ano.^[3] In Crohn disease the abscess and fistula appear to result from penetrating inflammation rather than gland infection.^[3] Other risk factors include inflammatory bowel disease generally, radiation, malignancy, pre-existing incontinence and chronic diarrhoea.^[3]

Faecal incontinence. Independent risk factors include older age, smoking, obesity, limited physical activity, neurologic disease, diabetes mellitus, frequent and loose stools and multiple comorbidities.^[4] It is more prevalent in Crohn disease, ulcerative colitis, coeliac disease and irritable bowel syndrome.^[4] Obstetric trauma is important in women: anal sphincter injury is clinically recognised in roughly 4% to 10% of vaginal deliveries, but occult damage may be present in 21% to 35% of women after vaginal delivery.^[4] Sphincter injury after anorectal operations (haemorrhoidectomy, sphincterotomy, fistula surgery), pelvic surgery or anal cancer treatment can also cause faecal incontinence.^[4]

Pruritus ani. Causes divide into secondary (haemorrhoids, fissure, fistula, abscess, proctitis, rectal cancer, adenomatous polyps, dermatitis, fungal infection in up to 15%, medications, systemic disease) and primary (idiopathic, in 25% to 75% of cases).^[6] Fungal infection accounts for up to 15% of underlying causes.^[6]

Everything follows from a small set of anatomical facts.

Haemorrhoids. The anal cushions contain arteriovenous channels. When their connective tissue support is damaged by straining or laxity, the cushions engorge, bleed and prolapse. Because the cushions normally contribute to continence, advanced prolapse (grades III and IV) may itself interfere with control. Haemorrhoids sit above or below the dentate line; the plexuses interconnect, which is why single-type disease is rare.

Anal fissure. The posterior midline is the site of about 73% of fissures.^[2] Higher resting tone in the internal sphincter reduces blood flow to the anoderm of the posterior commissure, producing ischaemia that converts a trivial tear into a wound that will not heal. A tense, painful sphincter also explains the "passing glass" pain of defecation.

Perianal abscess. Obstruction of an anal gland trap takes bacteria in; pus accumulates in the nearest space. Ischiorectal (or ischioanal) abscesses are the commonest, followed by intersphincteric, supralevator and submucosal collections.^[3] A horseshoe abscess crosses the midline in the deep postanal space. Supralevator abscesses may originate from an upward extension of an intersphincteric abscess (drain internally) or from a cephalad extension of an ischiorectal abscess (drain externally).

Fistula-in-ano. Chronic infection epithelialises the abscess drainage tract. The internal opening is usually at the dentate line. Goodsall's rule predicts the tract: an anterior external opening points radially toward the anus, while a posterior opening follows a curvilinear path to the posterior midline. The rule is generally accurate for anterior fistulas but less reliable for posterior ones.^[3] The sphincter relation (Parks) then governs continence risk and operation choice.

Pruritus ani. A vicious itch-scratch cycle: stimulation of sensory nerves causes scratching, skin injury, inflammation and more itching. Faecal soiling from transient sphincter relaxation, endopeptidases and potential allergens in stool contribute. Gordon's stages describe the skin from normal (stage 0) through red and inflamed (stage 1), white and lichenified (stage 2) to lichenified with ridges and ulceration from scratching (stage 3).^[6]

History. The cardinal symptom of internal haemorrhoids is painless bright red bleeding with defecation, sometimes as streaks on paper or drips into the pan.^[1] Intermittent tissue protrusion, mucus discharge, itching and difficulty with perineal hygiene occur. External haemorrhoids are often asymptomatic except for cleanliness problems; a thrombosed external haemorrhoid presents as a sudden, acutely painful non-reducible lump at the anal verge.

Examination. Inspect the anus at rest and then on straining. Digital rectal examination rules out other anorectal disease and assesses sphincter tone. Anoscopy assesses the anal canal. Rectal bleeding must never be assumed to be haemorrhoidal without the appropriate examination.

History and examination. The pain is sharp, tearing ("passing glass") and may persist for hours after a bowel movement. A sentinel skin tag at the distal margin and a hypertrophied anal papilla at the proximal margin suggest chronicity. Examination may be difficult because of spasm; in a doubtful or painful case examine under anaesthesia rather than force a diagnosis. Bright red bleeding is common.

Red flags within fissure. Lateral position, multiple (particularly also anterior and posterior) fissures, non-midline location, irregular or undermined edges, failure to heal or recurrence should make you think of secondary causes: Crohn disease, HIV, syphilis, tuberculosis, haematologic malignancy, anal cancer.^[2]

Anorectal pain and swelling are usual in superficial abscesses; spontaneous drainage and fever are less common. Deep (supralevator, high ischiorectal) abscesses may present with pain referred to the perineum, lower back or buttocks, and examination can be deceptively unremarkable; fever, immunocompromise and diabetes worsen risk.^[3]

Patients usually have a history of a drained abscess and report intermittent swelling and perianal discharge. Inspection finds an external opening, often with a track that can sometimes be felt or gently probed; scarring from previous surgery is common.

Ask about stool frequency, consistency, urgency, leakage of flatus, soiling, mucous discharge, pelvic pressure, obstetric history, previous anorectal surgery, diabetes, neurologic disease and medications. Map incontinence severity with a score such as the Wexner (Cleveland Clinic) score, in which a score of nine or more indicates significant impairment of quality of life, and a bowel diary counts episodes.

Itch is often worse after bowel movements, especially liquid stools and at night. Look for a red, excoriated (stage 1), lichenified (stage 2) or ridged and ulcerated (stage 3) perianal skin.^[6] The history should cover diet, hygiene practices, topical agents, medications, diabetes and bowel habit.

Anorectal pain, bleeding or a lump has a wider differential than haemorrhoids alone, and anal cancer can present identically.^[1]

Clinical examination first. Most diagnosis is clinical: inspection at rest and straining, digital rectal examination, anoscopy and, where needed, proctoscopy.^[3]

Endoscopic evaluation of the colon. Rectal bleeding must not automatically be attributed to haemorrhoids. A colonoscopy should be arranged when no obvious source is found, or with associated symptoms such as abdominal pain, distention or changing constipation, and in patients due for colorectal cancer screening.^[1]

Imaging. Routine imaging is not usually needed for abscess or fistula. It should be considered for an occult abscess, recurrent or complex fistula, immunosuppression or anorectal Crohn disease.^[3] In abscess/fistula evaluation, computed tomography has about 77% sensitivity for an abscess.^[3] Magnetic resonance imaging correctly identifies abscesses and grades the fistula tract with high sensitivity (95% sensitivity, 80% specificity and 97% positive predictive value for the primary tract in one prospective study), and better picks up secondary extensions in complex fistulas than endoanal ultrasound.^[3] Endoanal ultrasound is a useful sphincter and fistula tool in selected patients.^[3]

Other tests. Full blood count and inflammatory markers help in sepsis. Taking wound cultures is not usually useful in an uncomplicated abscess, except in recurrent, non-healing or HIV-related disease.^[3] For faecal incontinence, endoanal ultrasound and anorectal manometry (at least after failure of conservative treatment) help define sphincter and pelvic floor dysfunction; although manometry often does not change management, it identifies obstructed defecation.^[4]

There is no single score that diagnoses these diseases; diagnosis is clinical. Severity scores and criteria guide treatment instead.

• Haemorrhoid grade (Goligher I to IV) stages the patient for office versus operative treatment. Grade and symptoms together, not the grade alone, determine management.
• Acute versus chronic anal fissure is determined at six weeks of symptoms.^[2]
• Primary versus secondary anal fissure depends on cause; secondary causes must be excluded.
• Abscess severity depends on space involved, depth, horseshoe spread, immunosuppression and systemic sepsis. Composite "simple versus complex" fistula distinguishes a lay-open fistulotomy from sphincter-sparing operations.
• Faecal incontinence severity is measured by the Wexner score (score of 9 or more means significant quality of life impairment) and a bowel diary. ^[4]
• Pruritus stage (Gordon stages 0 to 3) grades skin damage.

The ASCRS 2024 guideline (Hawkins et al.) gives the hierarchy; ESCP 2020 and NICE CKS (UK) agree on conservative first-line care.

1. Lifestyle and bowel habit (first-line for all). Increase fibre and fluid, avoid straining and prolonged sitting, and correct constipation. In a Cochrane review of 7 randomised trials (378 patients), fibre reduced persistent symptoms (relative risk 0.47; 95% confidence interval 0.32 to 0.68) and bleeding (relative risk 0.50; 95% confidence interval 0.28 to 0.89); pruritus, prolapse and pain improved little. Constipation is more common in patients with haemorrhoids (odds ratio 2.09; 95% confidence interval 1.27 to 3.44).^[1]
2. Medical therapy. Topical agents (hydrocortisone, phenylephrine, pramoxine, witch hazel) give symptomatic relief with minimal harm; prolonged use can sensitise. Phlebotonics are associated with reductions in pruritus (odds ratio 0.23; 95% confidence interval 0.07 to 0.79), bleeding (0.12; 0.04 to 0.37), discharge and leakage (0.12; 0.04 to 0.42) and overall symptom improvement (15.99; 5.97 to 42.84), but no benefit for pain (0.11; 0.01 to 1.11), versus placebo in a Cochrane review of 24 randomised trials (2,334 patients).^[1] Hydrocortisone-pramoxine 1% foam controlled haemorrhoid symptoms in late pregnancy in a small prospective observational study of 88 patients, with no adverse fetal effects reported.^[1]
3. Office procedures (symptomatic grades I and II, selected grade III refractory to conservative care). Rubber band ligation is the most effective office treatment: in a single-centre retrospective study of 2,635 patients, 86.7% were asymptomatic at 8 weeks, with 15.5% symptomatic recurrence at 2 years; a Cochrane review of 3 randomised trials found surgery caused more pain (relative risk 1.94; 95% confidence interval 1.62 to 2.33) and complications (6.32; 1.15 to 34.89) than banding.^[1] Severe bleeding is a rare major complication at about 1%.^[1] Sclerotherapy can resolve bleeding in 69% to 88% of grade I and 90% to 100% of grade II prolapse, with 24% to 49% post-procedure pain and 0.90% to 6% bleeding.^[1] Infrared coagulation resolves bleeding in 78% (grade I), 52% (grade II) and 22% (grade III) haemorrhoids. Rubber band ligation is preferred in most patients.
4. Thrombosed external haemorrhoid. Early excision gives faster symptom resolution, reduced recurrence and longer remission: median time to symptom resolution was 3.9 days with excision versus 24 days with conservative treatment in one retrospective review (231 patients), and 97.3% of surgically treated patients had excision or thrombectomy. Conservative treatment nonetheless resolves symptoms in most patients, with median improvement at 5 days and complete resolution at 8 days in a review of 504 patients.^[1] Select carefully for early excision because of coagulopathy and anaesthetic risk.
5. Operative haemorrhoidectomy (select patients with external haemorrhoids, or combined internal and external disease grades III and IV). Open or closed excisional haemorrhoidectomy is effective; closed is associated with less pain, faster wound healing and less bleeding.39 Serious complications are rare: post-procedural haemorrhage in 1% to 2% and urinary retention in 1% to 15%. ^[1] Long-term complications include anal stricture and incontinence. Doppler-guided haemorrhoidal artery ligation may be used for internal haemorrhoids; recurrence ranges from 3% to 60% (pooled 17.5%) with an overall bleeding rate of 5%.^[1] Stapled haemorrhoidopexy is not routinely recommended as first-line surgical treatment because of marginal efficacy and significant risk (recurrent symptoms odds ratio 3.22; 95% confidence interval 1.59 to 6.51, and recurrent prolapse odds ratio 2.65; 1.45 to 4.85, compared with excision).^{[1] [2]}

Acute fissure (under six weeks). Non-operative treatment is safe and should usually be first-line: sitz baths, psyllium or other bulking agents, adequate fluids, simple analgesia and topical anaesthetic, with an avoidance of straining. Nearly half of patients resolve their symptoms with these measures. Sitz baths with fibre produced better pain relief than topical anaesthetic or hydrocortisone in a randomised trial of 103 patients (91% versus 60% versus 68%), and maintenance fibre reduced recurrence from 60% to 16% versus placebo. Healing falls as duration rises: 100% healing under one month versus 33.3% over six months.^[2]

Chronic fissure (six weeks or longer). Management must be individualised; lateral sphincterotomy can cause incontinence that may only appear years later.

• Topical nitroglycerin heals roughly 50% of chronic fissures. A Cochrane meta-analysis of 18 randomised trials (734 patients) found nitrates reduced persistence or recurrence (odds ratio 0.35; 95% confidence interval 0.19 to 0.65). Severe headache limits use: 2%, 6.5% and 24% with 0.1%, 0.2% and 0.4% glyceryl trinitrate respectively, with no better healing at higher doses (47%, 40% and 54% healing respectively, p = 0.3); headache occurs in at least 30% and stops treatment in up to 20% of patients.^[2]
• Topical calcium channel blockers (for example diltiazem cream) have similar efficacy to nitrates, a better side-effect profile, and can be first-line treatment. A small randomised trial in 45 patients found healing of 54.9% (glyceryl trinitrate) versus 66.7% (diltiazem, p = 0.2); a 2013 systematic review (238 patients, 7 trials) found diltiazem had fewer side effects (relative risk 0.48; 95% confidence interval 0.27 to 0.86) and headache (0.39; 0.24 to 0.66), with no difference in healing (1.10; 0.90 to 1.34). Topical delivery is preferred over oral, because systemic effects occur in 4.3% (topical) versus 38.0% (oral).^[2]
• Botulinum toxin (typically 20 to 60 units injected) gives healing similar to topical therapy as first-line, and modest improvement as second-line after failed topical treatment. A meta-analysis of 1,577 patients reported healing rates of 33% to 96% and a 5% incidence of transient faecal incontinence, with lesser dependence on dose than expected. Prospective comparisons show healing in about 67% with botulinum toxin versus 71% with topical therapy.^[2]
• Lateral internal sphincterotomy (LIS). For chronic fissure without baseline incontinence, LIS has the highest healing rates (88% to 100%) but causes faecal incontinence in 8% to 30% in follow-up of up to six years. Offer it as first-line in carefully selected patients who have no incontinence, previous obstetric injury, inflammatory bowel disease, previous anorectal operation or sphincter injury; for these, use medical therapy or an anocutaneous flap. Tailored (limited-to-apex) sphincterotomy achieves similar healing (95% to 100%) with lower incontinence rates (for example 2% versus 11%).^[2]
• Anocutaneous flap is a sphincter-preserving alternative for high-risk patients, with healing of 81% to 100% and faecal incontinence of 0% to 6%.^[2]
• Anal dilatation is inferior to sphincterotomy (incontinence odds ratio 4.03; 95% confidence interval 2.04 to 7.96 for dilatation) and is not recommended.^[2]

Treat acutely with prompt incision and drainage; do not delay. The incision should be large enough for adequate drainage, close to the anal verge, with sphincter protection. Supralevator and intersphincteric abscesses may need internal drainage. Irrigation and drainage without packing give equivalent or superior resolution with less pain than packing in randomised trials, and abscesses recur in up to 44% of patients within one year, especially with inadequate drainage, loculation, horseshoe abscess or omitted primary fistulotomy.^[3]

Primary fistulotomy at the time of drainage can reduce recurrence (relative risk 0.13; 95% confidence interval 0.07 to 0.24) but may increase continence disturbance; it is appropriate for selected simple fistulas after weighing continence risk. A staged seton can preserve or divide sphincter gradually. Neutropenic or immunosuppressed patients (absolute neutrophil count under 1,000 per cubic millimetre) may be treated with antibiotics before or instead of immediate incision and drainage. Antibiotics are otherwise reserved for cellulitis, systemic signs of infection, or immunosuppression. Methicillin-resistant Staphylococcus aureus should be suspected in recurrent infection and treated with targeted therapy when systemic sepsis is present.^[3]

Simple fistula with normal sphincter function. Fistulotomy (lay-open) is the treatment of choice, with healing in more than 90%. Marsupialisation improves wound healing; topical 10% sucralfate or 2% phenytoin reduces pain. Fistulectomy is less favoured. Risk factors for postoperative continence disturbance include pre-existing incontinence, recurrent fistula, female sex, complex fistula and previous anorectal surgery. Combined obstetric and fistula disease needs careful selection. ^[3]

Complex fistula. Preserve sphincter function: endorectal advancement flap (66% to 87% healing after first flap), ligation of the intersphincteric fistula tract (success 76%, complication 14%, incontinence 1.4% in a meta-analysis of 1,378 procedures), cutting or draining setons, or procedural variants. Anal fistula plug and fibrin glue are relatively ineffective (24% and 18% healing respectively). Minimally invasive techniques (video-assisted anal fistula treatment, FiLaC, endoscopic clipping) have reasonable short-term healing but unknown long-term outcomes. Complex fistula and rectovaginal fistula need cause-based multidisciplinary management, with initial non-operative management for three to six months after obstetric injury; Crohn fistula starts with medical therapy plus sepsis control. ^[3]

First-line management is conservative. 22% to 54% of patients improve with behavioural and dietary modification. Assessment includes obstetric and surgical history, stool diary, medicines, neurologic disease and pelvic floor disorders; Wexner scoring; examination for soiling, patulous anus, prolapse, mass and stricture; endoanal ultrasound and anorectal manometry if initial treatment fails. ^[4]

Management steps:

• Diet and bowel habit: fibre titration, fluids, avoidance of triggers (caffeine, artificial sweeteners, lactose, gluten). Fibre reduced incontinent stools to less than half versus placebo in 39 patients. ^[4]
• Medication: antidiarrhoeals such as loperamide or diphenoxylate-atropine for diarrhoea-predominant symptoms; bulking agents to thicken stool; cholestyramine for bile acid diarrhoea.
• Skin care: zinc oxide barrier creams, gentle soap, wipes, pads.
• Bowel training, transanal irrigation and biofeedback (reported 64% to 89% improvement in selected series) for persistent symptoms. ^[4]
• Surgery when conservative therapy fails: sphincter repair, sacral nerve stimulation, injectable bulking agents, artificial sphincter or conduit; evidence- and centre-dependent. Treat underlying disease (inflammatory bowel disease, overflow from constipation, neoplasia); avoid mistaking constipation for diarrhoea.
• Record Wexner scores before and after to monitor change.

Treat the cause first: haemorrhoids, fissure, fistula, abscess, proctitis, infection (fungal in up to 15% of cases), dermatosis and neoplasia. For idiopathic disease:

• Reassure and educate: keep perianal skin dry and clean, wash with water not soap, avoid excess scrubbing and scratching, dry with a hair dryer or dab with cotton, wear loose cotton underwear.
• Avoid triggers. Several foods and drinks are implicated: coffee, tea, cola, chocolate, beer, milk and dairy, tomatoes, citrus and spices. Coffee is associated with lowered resting anal pressure. Evidence is inconsistent, so advise trial avoidance rather than strict prohibition.
• Barrier creams such as zinc oxide protect skin; psyllium may improve hygiene.
• Short courses of 1% hydrocortisone cream improve symptoms (68% improvement in a randomised crossover trial); avoid prolonged steroid use because of atrophy, infection, dermatitis, telangiectasia and purpura. ^[6]
• Alternative reported treatments include 0.006% topical capsaicin and intradermal methylene blue for intractable cases, with appropriate specialist input.
• If pruritus persists beyond two to three weeks of conservative treatment, search for underlying disease, including colonoscopy in patients over 50 or with long-standing refractory symptoms, because neoplastic lesions are more likely with long duration and age over 50.

• Unexplained anal mass or unexplained anal ulceration should lead to a suspected cancer pathway referral for anal cancer (NICE NG12).
• Any rectal mass requires referral for colorectal cancer.
• Atypical features of fissure (lateral position, multiple fissures, non-midline location, irregular edges, failure to heal or recurrence) warrant investigation for Crohn disease, HIV, syphilis, tuberculosis, haematologic malignancy and anal cancer, with a low threshold for examination under anaesthesia and biopsy.
• Persistent haematochezia after apparently successful haemorrhoid treatment, or bleeding with change in bowel habit, abdominal symptoms or iron-deficiency anaemia, requires endoscopic evaluation.
• Immunocompromised status, HPV-related disease, chronic anal fistula in Crohn disease, and new anorectal symptoms in older adults all lower the threshold for biopsy.
• Anal cancer can present identically to benign anorectal disease; if there is any doubt, biopt and refer.
• Suspected cancer referral criteria as above are derived from NICE NG12 (last updated 15 April 2026) and from the ASCRS anal squamous cell cancer guideline 2018. ^[5]

• Haemorrhoids. Prolapse, bleeding (significant haemorrhage after banding in about 1%), thrombosis, strangulation with necrosis, urinary retention (1% to 15% after excisional haemorrhoidectomy), anal stricture, and incontinence after surgery.
• Anal fissure. Chronicity, abscess and fistula formation, recurrence after incomplete treatment, and faecal incontinence after sphincterotomy (8% to 30% over long follow-up).
• Perianal abscess. Recurrence (up to 44% within one year), fistula formation, necrotising infection in susceptible patients, and continence disturbance from surgery. ^[3]
• Fistula-in-ano. Recurrent abscess, multiple operations, sphincter loss with incontinence, chronic pain.
• Faecal incontinence. Skin breakdown, social isolation, mood disorder, and nursing home placement when severe.
• Pruritus ani. Skin fissuring and secondary infection from chronic scratching, and missed neoplasia if refractory disease is treated symptomatically alone.

• Acute anal fissure heals within six weeks in roughly half of patients with conservative treatment; chronic healing falls to about one-third in prolonged symptoms; sphincterotomy cures 88% to 100% with late incontinence in 8% to 30%.
• Abscess recurs in up to 44% within one year; 30% to 70% of abscess patients have a concurrent fistula and a further 30% to 50% develop one later.
• Haemorrhoidal recurrence after rubber band ligation is around 15.5% at two years; haemorrhoidectomy gives durable control but postoperative bleeding occurs in 1% to 2%.
• Faecal incontinence improves with conservative measures in a quarter to a half of patients and often needs multidisciplinary and surgical escalation.
• Pruritus usually resolves when the underlying cause is found; idiopathic disease needs ongoing hygiene and lifestyle management.
• Simple low fistulotomy cures more than 90% of appropriate patients; endorectal flap and LIFT have documented success rates of 66% to 87% and 76% respectively.

• Prevention of haemorrhoids and fissure is prevention of constipation and straining: fibre (about 25 to 35 g daily), fluids, regular activity and cessation of prolonged toileting; the role of fibre is well established for bleeding and symptoms, though optimum daily intake is individualised.
• Behaviour change is the first step for faecal incontinence, with good long-term outcomes in many patients.
• Pruritus prevention: gentle hygiene, barrier creams, avoidance of overwashing and dermatitis.
• Red flags must be sought during every anorectal consultation. Persistent bleeding should trigger colorectal evaluation.
• No universal screening of asymptomatic patients for haemorrhoids or fissure is recommended. Colorectal cancer screening follows national guidelines.

Pregnancy and the puerperium. Haemorrhoids and fissures are common; conservative care (diet, fibre, fluids, sitz baths, topical therapies) is first-line, and hydrocortisone-pramoxine 1% foam has been used safely in late pregnancy in a small prospective observational study of 88 patients. Avoid excessive medication. Postpartum faecal incontinence from sphincter injury needs specialist assessment rather than reassurance, because clinically recognised sphincter injury occurs in 4% to 10% of vaginal deliveries.

Children. Anal fissures occur in infants, often posterior and associated with constipation or diarrhoea; treatment is conservative, with laxatives and hygiene education. Perianal abscess in children needs drainage; fistula is less common and management must protect the sphincter. Pruritus in children should raise pinworm infection, treated by family treatment and hygiene. Haemorrhoids are rare in children and should prompt search for underlying disease.

Older adults. A "new" fissure or a lateral or multiple fissure in an older patient is secondary until proven otherwise; bleeding and anaemia need lower gastrointestinal evaluation. Faecal incontinence prevalence rises and is often multifactorial; treat bowel and continence function, review medicines. Beware anal cancer masquerading as haemorrhoids.

Immunocompromised patients. Anorectal sepsis can be lethal. Neutropenic patients with abscess may need antibiotics first and often benefit from cultures and imaging. HIV-related anorectal infection may be atypical (tuberculosis, sexually transmitted infection). Fistula in Crohn disease needs multidisciplinary medical and surgical care, starting with control of sepsis.

• Most of these diagnoses can be made on history and examination without imaging or laboratory tests, even when endoscopy is unavailable.
• Anoscopy may be improvised or absent; do not delay drainage of a superficial abscess awaiting instruments that are not needed.
• Fibre, fluids and sitz baths are cheap first-line treatments everywhere; rubber band ligation and excisional haemorrhoidectomy are established and economical.
• Rigid versus flexible endoscopy availability varies; a rectal examination plus a good history can still identify red flags.
• Complex fistula, suspected cancer and necrotising infection need referral to a surgical centre.
• Specimens and drained abscesses should go for histology whenever possible; tissue diagnosis is the final arbiter when malignancy is a concern.

• Haemorrhoids are benign vascular cushions, graded I to IV by prolapse, with stepwise management from lifestyle to office procedures to haemorrhoidectomy.
• Rectal bleeding is not automatically haemorrhoidal: excluded, malignancy, inflammatory bowel disease, infection or distal colorectal pathology must be considered with history, examination and endoscopy when indicated.
• Anal fissure is a split driven by sphincter hypertonicity and ischaemia, 73% being posterior; acute (under six weeks) usually heals conservatively; chronic fissure may need nitroglycerin, calcium channel blockers, botulinum toxin or tailored sphincterotomy.
• Sphincterotomy cures most chronic fissures but carries an 8% to 30% risk of faecal incontinence, so selection matters.
• The cryptoglandular abscess-fistula spectrum is treated by prompt drainage; recurrence is up to 44% in one year; fistula follows in one-half to two-thirds of cases, classified by Parks.
• Goodsall predicts an anterior radial tract and a posterior (curvilinear) tract, and is less reliable posteriorly.
• Red flags: lateral or multiple (non-midline) fissure, atypical edges, non-healing or recurrent fissure, any anal mass or ulceration, persistent post-treatment bleeding, immunosuppression. Refer for cancer.
• The perianal abscess is an emergency to drain, not to treat only with antibiotics, except in the neutropenic.
• Simple fistula treated by lay-open fistulotomy cures over 90%; complex fistula needs sphincter-sparing operations with documented success rates.
• Faecal incontinence is common and treatable; begin with diet, skin care, bowel training and biofeedback, with surgery as a later step.
• Pruritus ani is a symptom with many secondary causes, dominated by hygiene, treatment of underlying anorectal disease and short-course 1% hydrocortisone.
• Age over 50, long duration and refractory pruritus warrant exclusion of neoplasia.
• Use suspected cancer pathway referral for unexplained anal mass or anal ulceration, specialist referral for complex fistula, Crohn disease and recurrence, and biopsy or histology when doubt persists.

Benign anorectal disease sits within gastrointestinal surgery. Related MedGrasp topics are haemorrhoid care, inflammatory bowel disease, colorectal cancer screening and recognition, perianal Crohn disease, functional bowel disorders, constipation and faecal incontinence, anal cancer, anorectal infections, dermatologic perianal disease and colorectal cancer red-flag guidance.

Guideline recommendations and reported rates vary between studies and populations, so management should follow local protocol, multidisciplinary review and the patient's continence reserve.