Anorectal Disorders

📋 Key Information Summary

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Haemorrhoids are the most common anorectal condition in Australian general practice, affecting up to 40% of adults over 50 years; most are managed conservatively with fibre supplementation, topical agents, and lifestyle modification.
Anal fissure presents with sharp pain on defecation and bright red rectal bleeding; chronic fissures (≥6 weeks) require topical GTN or diltiazem ointment before surgical consideration.
Perianal abscess is a surgical emergency requiring prompt incision and drainage; antibiotics alone are insufficient — up to 50% develop a fistula-in-ano.
Pilonidal sinus predominantly affects young males (15–30 years); acute abscess requires drainage; definitive surgery (excision ± flap) is reserved for recurrent or chronic disease.
Faecal incontinence affects 2–15% of community-dwelling Australians and is significantly underreported; obstetric sphincter injury is the leading cause in women.
Rectal prolapse in adults usually requires surgical repair (e.g., ventral mesh rectopexy); in children, it is almost always self-limiting and managed conservatively.
Rectal bleeding demands systematic evaluation — while haemorrhoids are the most common cause, always exclude colorectal cancer, inflammatory bowel disease, and angiodysplasia, especially in patients aged ≥45 years.
Red-flag features — change in bowel habit, weight loss, iron-deficiency anaemia, new onset age ≥45, or family history of colorectal cancer — warrant urgent colonoscopy referral.
Digital rectal examination (DRE) and rigid/flexible sigmoidoscopy are essential first-line investigations in primary care for all anorectal presentations.
Aboriginal and Torres Strait Islander peoples have higher rates of colorectal cancer with later-stage presentation and lower screening participation; culturally safe engagement and proactive referral are critical.
Stool softeners (e.g., macrogol 3350, docusate) are a cornerstone adjunct in nearly every anorectal condition to reduce straining and recurrence.
When to refer urgently: large or circumferential haemorrhoids (Grade III–IV), chronic fissure unresponsive to 8 weeks of medical therapy, perianal abscess with systemic sepsis, full-thickness rectal prolapse, or any rectal bleeding with red-flag features.

Introduction & Australian Epidemiology

Anorectal disorders encompass a broad spectrum of benign and malignant conditions affecting the anal canal, perianal skin, and distal rectum. These conditions are exceedingly common in Australian general practice, accounting for a significant proportion of surgical referrals and ambulatory presentations. Despite their prevalence, many patients delay seeking care due to embarrassment, leading to diagnostic delays and avoidable complications.

In Australia, haemorrhoids affect an estimated 30–40% of adults over the age of 50, with symptomatic haemorrhoids representing one of the most frequent reasons for gastroenterological and surgical consultation. Anal fissure has an annual incidence of approximately 1 in 350 adults, with a bimodal distribution peaking in young adults and middle-aged women. Perianal abscess occurs predominantly in males aged 20–40 years, with an annual incidence of roughly 10 per 100,000 population.

Colorectal cancer remains Australia's second most common cause of cancer-related mortality, with over 15,000 new diagnoses annually (Australian Institute of Health and Welfare, 2023). Rectal bleeding is the presenting symptom in up to 35% of colorectal cancers, underscoring the importance of systematic evaluation rather than reflex attribution to benign causes.

This article provides a comprehensive Australian primary care and surgical perspective on the diagnosis and management of common anorectal disorders, including anal fissure, haemorrhoids, perianal abscess, pilonidal sinus, faecal incontinence, rectal prolapse, and rectal bleeding. Management recommendations are aligned with Therapeutic Guidelines (eTG), the Royal Australian College of General Practitioners (RACGP), the Colorectal Surgical Society of Australia and New Zealand (CSSANZ), and relevant Australian and international consensus statements.

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Clinical Pearl: Never attribute rectal bleeding to haemorrhoids without a thorough clinical assessment including DRE and, where indicated, endoscopic evaluation. Missed colorectal cancer in the context of "haemorrhoidal bleeding" is a recognised source of medicolegal risk in Australian general practice.

Anal Fissure & Haemorrhoids

Anal Fissure

An anal fissure is a linear tear or ulcer in the squamous epithelium of the anal canal, distal to the dentate line. It is one of the most common causes of anorectal pain and rectal bleeding in younger adults. The pathophysiology involves a cycle of internal anal sphincter hypertonia, reduced anodermal blood flow, and impaired healing.

Classification

Feature	Acute Fissure (<6 weeks)	Chronic Fissure (≥6 weeks)
Appearance	Superficial, linear tear; well-demarcated edges	Deep ulcer; sentinel skin tag (distal), hypertrophied anal papilla (proximal)
Location	Posterior midline (80–90%)	Posterior midline; anterior midline in women
Symptoms	Sharp pain on defecation, bright red blood on paper	Persistent pain, spasm, bleeding, cyclical pattern
First-line Rx	Conservative (fibre, sitz baths, topical GTN)	Topical GTN 0.2–0.4% or diltiazem 2% ointment ± botulinum toxin

Management of Anal Fissure

1

Conservative measures (all patients)

Dietary fibre supplementation (psyllium husk 3–6 g/day or ispaghula), adequate oral hydration (≥1.5 L/day), warm sitz baths (10–15 min BD), stool softeners (macrogol 3350 or docusate sodium), and avoidance of straining.

2

Pharmacological (if conservative measures fail at 2–4 weeks)

Glyceryl trinitrate (GTN) 0.2–0.4% ointment applied perianally BD for 8 weeks, OR diltiazem 2% ointment BD for 8 weeks (less headache). Compounding pharmacy often required for GTN; diltiazem 2% available as Rectogesic® (0.2% GTN is PBS-listed; 0.4% may require authority).

3

Second-line / specialist referral

Botulinum toxin A injection (20 units into internal sphincter) performed by colorectal surgeon, or lateral internal sphincterotomy (gold standard surgical cure rate 90–95%, but risk of flatus/faecal incontinence ~5–10%). Reserved for refractory cases.

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Glyceryl Trinitrate (GTN) 0.2% Ointment

Rectogesic® · Topical nitric oxide donor

Adult dose Apply 1 cm ribbon to perianal skin BD (morning and night) for 8 weeks

Paediatric dose Not routinely recommended in children; use conservative measures first

Common side effects Headache (up to 50%), dizziness, local irritation

Renal adjustment None required

PBS status ✔ PBS General Benefit

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Diltiazem 2% Ointment

Compounded · Calcium channel blocker (topical)

Adult dose Apply 1 cm ribbon perianally BD for 8 weeks

Advantage Less headache than GTN; similar efficacy

Renal adjustment None required

PBS status ✘ Not PBS-listed (compounded)

Haemorrhoids

Haemorrhoids (piles) are swollen vascular cushions in the anal canal arising from the internal or external haemorrhoidal plexus. They are classified by grade and position (internal vs external vs mixed). Risk factors include chronic constipation, straining, pregnancy, low-fibre diet, portal hypertension, and obesity.

Classification of Internal Haemorrhoids

Grade I

Non-prolapsing

Haemorrhoids remain above the dentate line; visible only on proctoscopy. May cause painless bright red bleeding.

Setting: GP — conservative management

Grade II

Prolapse with straining, spontaneous reduction

Prolapse through the anal canal on defecation or straining; reduces spontaneously. Bleeding, pruritus, and mucous discharge common.

Setting: GP ± specialist for rubber band ligation

Grade III

Prolapse requiring manual reduction

Prolapse requiring digital replacement. May be associated with thrombosis, significant bleeding, and discomfort.

Setting: Specialist referral — banding, sclerotherapy, or surgery

Grade IV

Irreducible prolapse

Permanently prolapsed, cannot be reduced. Risk of strangulation, gangrene, and massive haemorrhage.

Setting: Urgent surgical referral — haemorrhoidectomy

Management of Haemorrhoids

1

Conservative (Grade I–II)

High-fibre diet (≥30 g/day), fibre supplements (psyllium, sterculia), adequate fluids, stool softeners, avoidance of straining and prolonged sitting on the toilet, warm sitz baths. Topical preparations (local anaesthetic ± hydrocortisone) for short-term symptom relief (≤7 days).

2

Office-based procedures (Grade II–III)

Rubber band ligation (RBL) — most common, 70–80% cure rate; sclerotherapy (phenol in oil injection); infrared coagulation. Performed in outpatient colorectal clinic under direct vision.

3

Surgical (Grade III–IV or failed conservative)

Haemorrhoidectomy (excisional — Milligan-Morgan or Ferguson technique) — gold standard for advanced disease. Stapled haemorrhoidopexy (PPH) — less pain but higher recurrence rate. Haemorrhoidal artery ligation (THD/Doppler-guided) — emerging option. MBS item 30740.

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Thrombosed external haemorrhoid: Presents as an acutely painful, blue-purple perianal lump within 48–72 hours of onset. If seen within 72 hours, excision of the thrombosed haemorrhoid under local anaesthesia provides immediate relief. If >72 hours, conservative management (analgesia, ice, stool softeners) is preferred as the thrombus begins to organise.

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Macrogol 3350 (Polyethylene Glycol)

Movicol® · Osmotic laxative / stool softener

Adult dose 1–3 sachets daily, dissolved in 125 mL water per sachet; titrate to soft stool

Paediatric dose ½–1 sachet daily (age <6 years); 1–2 sachets daily (6–12 years)

Renal adjustment Use with caution in severe renal impairment (electrolyte content)

PBS status ✔ PBS General Benefit

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Lidocaine + Hydrocortisone Topical

Proctosedyl® · Local anaesthetic + anti-inflammatory

Adult dose Apply to affected area BD and after each bowel motion for ≤7 days

Note Short-term use only; chronic use may cause skin atrophy and sensitisation

PBS status ✔ PBS General Benefit

Perianal Abscess & Pilonidal Sinus

Perianal Abscess

A perianal abscess arises from infection of the anal glands (cryptoglandular theory) at the level of the dentate line, tracking into the perianal, ischiorectal, intersphincteric, or supralevator spaces. It is the most common anorectal emergency and is approximately twice as common in males than females. Up to 50% of patients who develop a perianal abscess will subsequently develop a fistula-in-ano.

Classification by Anatomical Space

Type	Frequency	Clinical Features	Management
Perianal	~60%	Superficial, painful swelling adjacent to the anus; visible erythema and fluctuance	I&D under local anaesthesia in ED or office
Ischiorectal	~20%	Deep, diffuse perineal swelling; systemic illness; less visible externally	I&D under GA or regional anaesthesia
Intersphincteric	~5%	Severe anal pain; minimal external signs; may be palpable on DRE	Specialist drainage; MRI if equivocal
Supralevator	<5%	Pelvic pain; may mimic pelvic pathology; often iatrogenic or Crohn's-related	Specialist drainage; CT/MRI pelvis
Fournier's gangrene	Rare	Necrotising fasciitis of the perineum; rapidly progressive, crepitus, sepsis, multi-organ failure	Immediate surgical debridement + broad-spectrum IV antibiotics (meropenem + vancomycin); ICU

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Fournier's gangrene: A life-threatening necrotising fasciitis of the perineum. Presents with rapidly spreading erythema, crepitus, pain disproportionate to examination, and systemic sepsis. Mortality 20–40%. Requires immediate surgical debridement, broad-spectrum IV antibiotics, and ICU admission. Do not delay for imaging if clinical suspicion is high.

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Immunocompromised patients: Perianal abscess in patients with diabetes mellitus, HIV/AIDS, neutropenia, or those on immunosuppressants (including biologics) may present atypically and progress rapidly. Always consider Crohn's disease in recurrent or complex perianal sepsis.

Management of Perianal Abscess

Incision and drainage (I&D) is the definitive treatment for all perianal abscesses. Antibiotics alone are inadequate. The procedure involves:

Incision as close to the anal verge as possible (to minimise fistula tract length)
Breakdown of all loculations with digital exploration
Excision of overlying skin ellipse (to prevent premature closure)
Packing with saline-soaked gauze or wound wick; sitz baths from 48 hours
Search for internal opening (Goodsall's rule for fistula prediction)

Antibiotics are NOT routinely required for simple perianal abscess after adequate I&D. Reserve antibiotics for:

Surrounding cellulitis (erythema >2 cm from wound edge)
Systemic signs (fever >38°C, tachycardia, raised WCC/CRP)
Immunocompromised patients
Valvular heart disease or prosthetic material (endocarditis prophylaxis per current guidelines)
Fournier's gangrene or necrotising infection

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Amoxicillin + Clavulanate

Augmentin® · Beta-lactam / beta-lactamase inhibitor

Adult dose (oral) 875/125 mg PO BD for 5–7 days (cellulitis adjunct)

Adult dose (IV) 1.2 g IV TDS (severe infection)

Paediatric dose 25/3.6 mg/kg PO BD or 30/4.5 mg/kg IV TDS

Renal adjustment eGFR 10–30: 875/125 mg PO BD; eGFR <10: 500/125 mg PO BD

PBS status ✔ PBS General Benefit

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Metronidazole

Flagyl® · Nitroimidazole antibiotic (anaerobic cover)

Adult dose 400 mg PO TDS for 5–7 days (combined with amoxicillin + clavulanate)

Paediatric dose 7.5 mg/kg PO/IV TDS (max 400 mg/dose)

Important Avoid alcohol (disulfiram-like reaction); metallic taste; peripheral neuropathy with prolonged use

PBS status ✔ PBS General Benefit

Pilonidal Sinus

Pilonidal disease is a chronic inflammatory condition of the natal cleft, most common in young males aged 15–30 years with risk factors including hirsutism, obesity, sedentary occupation, and prolonged sitting. The pathogenesis involves hair follicle penetration creating a foreign-body granulomatous reaction and secondary infection.

Management

1

Acute pilonidal abscess

Incision and drainage ± excision of the sinus tract in the same sitting. Off-midline incision preferred to reduce recurrence. Hair removal from the natal cleft (shaving or laser). Wound left open to heal by secondary intention.

2

Chronic / recurrent pilonidal sinus

Definitive surgical excision — wide local excision with healing by secondary intention, Limberg flap (rhomboid flap), or Bascom cleft lift procedure. Flap techniques have lower recurrence rates (2–5% vs 10–30%) and faster return to work.

3

Conservative (limited disease)

Regular hair removal, meticulous perineal hygiene, phenol application for small tracts, sinus excision (pit-picking technique). Most appropriate for first episode with minimal symptoms.

Anal Incontinence & Rectal Prolapse

Anal (Faecal) Incontinence

Faecal incontinence (FI) is defined as the involuntary loss of solid or liquid stool. It affects 2–15% of community-dwelling Australians, with prevalence rising to 50% in residential aged care facilities. Despite its high prevalence, FI is significantly underreported due to patient embarrassment. It is a leading cause of nursing home admission in the elderly.

Aetiology

Category	Causes
Sphincter disruption	Obstetric injury (3rd/4th degree perineal tear — most common in women), iatrogenic (sphincterotomy, fistula repair, haemorrhoidectomy), trauma
Neurological	Pudendal neuropathy (chronic straining, obstetric, diabetes), spinal cord injury, cauda equina, multiple sclerosis, stroke
Structural	Rectal prolapse, rectocele, large internal haemorrhoids
Functional	Overflow incontinence (faecal impaction), diarrhoea-predominant IBS, cognitive impairment
Inflammatory	Ulcerative colitis, Crohn's disease, radiation proctitis

Assessment

History: Type of incontinence (urge vs passive), frequency, severity, impact on QoL, obstetric history, surgical history, bowel habit, medication review (laxatives, metformin, PPIs).
Examination: Perianal inspection (skin excoriation, scarring, prolapse), DRE (resting and squeeze tone, sensation), perineal descent assessment.
Validated scoring: Wexner (Cleveland Clinic) Incontinence Score or St Mark's (Vaizey) Score for severity grading.
Specialist investigations: Endoanal ultrasound (gold standard for sphincter defects), anorectal manometry, pudendal nerve terminal motor latency (PNTML), defecating proctography or MRI defecography.

Available

Endoanal Ultrasound

Gold standard for internal and external sphincter defects. Available at most tertiary hospitals. MBS item 55068.

Referral

Anorectal Manometry

Assesses resting/squeeze pressures and rectal sensation. Available at specialist GI physiology labs. MBS item 12250.

Referral

MRI Defecography

Dynamic assessment of pelvic floor and rectal evacuation. Identifies rectocele, intussusception, and pelvic floor dyssynergia. MBS item 63536.

Available

Faecal Calprotectin

Excludes inflammatory bowel disease as an underlying cause. MBS item 66821 (bulk-billed in most settings).

Management of Faecal Incontinence

1

Conservative (all patients)

Bowel habit optimisation (fibre, fluids, stool bulking agents), toilet timing/scheduled toileting, pelvic floor physiotherapy (biofeedback for 3–6 months), skin care (barrier creams, incontinence pads), treatment of diarrhoea or constipation. Referral to continence nurse specialist (Continence Foundation of Australia: 1800 33 00 66).

2

Pharmacological

Loperamide 2–4 mg PRN (max 16 mg/day) for urge incontinence with loose stool; increases internal sphincter tone. Codeine phosphate 30–60 mg PRN as second-line. Avoid bulk-forming agents with loose stool (may worsen).

3

Specialist / Surgical

Sphincter repair (overlap sphincteroplasty for obstetric defect — best outcomes within 6 months of injury), sacral nerve stimulation (SNS/neuromodulation — effective for idiopathic and some sphincter defects), injectable bulking agents (Solesta®), artificial bowel sphincter, magnetic anal sphincter (FENIX®), antegrade colonic irrigation (ACE procedure).

Rectal Prolapse

Rectal prolapse is the circumferential protrusion of the full thickness of the rectal wall through the anal canal. It must be distinguished from mucosal prolapse (internal or external) and rectal intussusception.

Classification

Mucosal

Mucosal (partial) prolapse

Protrusion of rectal mucosa only; radial folds; common in children and elderly. Usually self-limiting in paediatric population.

Setting: GP — conservative in children; specialist if persistent

Full thickness

Complete (full-thickness) rectal prolapse

All layers of the rectal wall protrude; concentric folds; associated with faecal incontinence (50–75%), constipation (25–50%), and mucous discharge.

Setting: Specialist surgical referral — usually requires operative repair

Internal

Internal rectal intussusception / occult prolapse

Rectum telescopes into itself without external protrusion; causes obstructed defecation, incomplete evacuation, and may lead to full prolapse. Diagnosed by defecating proctography or MRI.

Setting: Specialist assessment — biofeedback or surgery

Management of Rectal Prolapse

Children: Almost always mucosal and self-limiting. Treat underlying cause (constipation, diarrhoea, cystic fibrosis screening). Conservative measures: high-fibre diet, stool softeners, avoidance of straining. If persistent beyond age 3–5, consider injection sclerotherapy or Thiersch procedure (rarely needed).
Adults — perineal approach: Delorme procedure (mucosal stripping + plication) or Altemeier procedure (perineal rectosigmoidectomy). Suitable for high-risk / elderly patients unable to tolerate abdominal surgery. MBS item 32086.
Adults — abdominal approach: Ventral mesh rectopexy (VMR) — current gold standard with low recurrence (~3–5%) and lower rates of new-onset constipation compared with posterior rectopexy. Resection rectopexy (Frykman-Goldberg) for patients with pre-existing constipation. Laparoscopic approach preferred. MBS item 32088/32090.

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Loperamide

Imodium® · Opioid receptor agonist (peripheral)

Adult dose 2 mg initially, then 2 mg after each loose stool (max 16 mg/day); maintenance 2–4 mg BD

Mechanism Slows transit, increases internal anal sphincter tone, improves stool consistency

Caution Avoid in active IBD flare, acute dysentery, or suspected bacterial enteritis without antibiotics

Renal adjustment None required

PBS status ✔ PBS General Benefit

Rectal Bleeding — Causes & Presentation

Rectal bleeding (haematochezia) is one of the most common gastrointestinal symptoms presenting to Australian general practice, affecting up to 15% of adults annually. While the majority of cases are attributable to benign anorectal conditions, rectal bleeding is the presenting symptom in approximately 35% of colorectal cancers. A systematic, risk-stratified approach to evaluation is essential.

Differential Diagnosis by Age and Presentation

Cause	Typical Presentation	Age Group	Key Features
Haemorrhoids	Painless bright red blood on paper, in toilet bowl, or on stool surface	30–65 years	Most common cause; associated with straining, constipation, pregnancy
Anal fissure	Sharp pain on defecation with streaks of bright red blood	15–45 years	Posterior midline position; sentinel tag in chronic cases
Colorectal cancer	Dark or bright red blood, change in bowel habit, weight loss, iron deficiency	≥45 years (screening age)	Must be excluded in all patients ≥45 with rectal bleeding; National Bowel Cancer Screening Program (NBCSP) from age 45 (reduced from 50 in 2024)
Inflammatory bowel disease	Bloody diarrhoea, mucus, urgency, weight loss, extraintestinal manifestations	15–35 years (UC); bimodal (Crohn's)	Faecal calprotectin elevated; colonoscopy with biopsies required
Diverticular bleeding	Sudden onset, painless, large volume maroon or dark red blood	>60 years	Most common cause of major lower GI bleeding in the elderly; usually self-limiting
Angiodysplasia	Recurrent, painless, low-volume bright red bleeding	>60 years	Right colon most common; associated with aortic stenosis (Heyde syndrome), CKD, anticoagulants
Infectious colitis	Bloody diarrhoea, abdominal cramps, fever	Any age	C. difficile, Salmonella, Shigella, Campylobacter, E. coli O157; stool MC+S essential
Solitary rectal ulcer syndrome	Bleeding, mucus discharge, straining, sensation of incomplete evacuation	Young–middle aged adults	Associated with rectal prolapse and paradoxical puborectalis contraction

Risk Stratification — When to Refer Urgently

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Red-flag features requiring urgent investigation (colonoscopy within 30 days or urgent surgical referral):

Rectal bleeding in any patient ≥45 years without a benign anorectal cause confirmed on examination
Iron-deficiency anaemia (Hb <120 g/L in men, <115 g/L in women) with or without overt bleeding
Unintentional weight loss (>5% body weight in 6 months)
Change in bowel habit (new constipation or diarrhoea >6 weeks)
Family history of colorectal cancer (first-degree relative <55 years at diagnosis)
Positive faecal occult blood test (FOBT) from the National Bowel Cancer Screening Program
Abdominal or rectal mass on examination
Large-volume or haemodynamically significant bleeding

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Age threshold update: In 2024, the Australian Government lowered the NBCSP starting age from 50 to 45 years. All Australians aged 45–74 receive a free immunochemical faecal occult blood test (iFOBT) every 2 years. A positive test warrants colonoscopy referral within 30 days. GPs should encourage participation, particularly in under-screened populations.

Approach to Rectal Bleeding in Primary Care

1

History & red-flag assessment

Character of bleeding (colour, volume, frequency, relationship to stool), associated symptoms (pain, change in bowel habit, weight loss, tenesmus, mucus), family history, medication review (anticoagulants, NSAIDs, antiplatelets), prior episodes.

2

Examination

Vital signs (haemodynamic stability), abdominal examination, perianal inspection, DRE (tone, masses, fissure, haemorrhoids, stool colour), rigid sigmoidoscopy (identify source within 15–20 cm).

3

Initial investigations

FBC (anaemia, thrombocytopaenia), ferritin and iron studies (iron deficiency), CRP/ESR (inflammation), stool MC+S and C. difficile toxin if diarrhoea present, faecal calprotectin (exclude IBD), iFOBT if not already done.

4

Referral pathway

No red flags + confirmed benign source → treat locally and review in 4–6 weeks. Red flags or age ≥45 without confirmed benign cause → urgent colonoscopy referral (<30 days). Haemodynamic instability → ED / acute surgical admission. Ongoing bleeding with haemodynamic compromise → CT angiography ± interventional radiology embolisation.

Investigations Summary

Essential

Full Blood Count (FBC) + Iron Studies

Assess for iron-deficiency anaemia. Microcytic hypochromic picture suggests chronic blood loss. MBS item 66551 (FBC), 66573 (iron studies).

Essential

Digital Rectal Examination + Rigid Sigmoidoscopy

Identifies the source of bleeding in up to 70% of cases. Can be performed in GP rooms. MBS item 104 (DRE), 105 (sigmoidoscopy).

Available

Faecal Calprotectin

Screening test for IBD. Sensitivity ~95%, specificity ~80% for IBD. Levels >250 μg/g strongly suggest IBD. MBS item 66821.

Available

Immunochemical FOBT (iFOBT)

NBCSP screening test; also available on request. More sensitive than older guaiac-based tests. MBS item 66777 (not routinely billed; NBCSP is free).

Referral

Colonoscopy

Gold standard for visualising the entire colon and rectum with biopsy capability. Required for red-flag symptoms, positive FOBT, suspected IBD or cancer. MBS item 32222.

Referral

CT Angiography / Interventional Embolisation

For acute, haemodynamically significant lower GI bleeding where colonoscopy cannot identify the source. Interventional radiology for selective embolisation. MBS item 57353 (CT angiography).

Monitoring

0–2 weeks

Initial follow-up after diagnosis: assess response to conservative measures (fibre, sitz baths, topical agents). Confirm bleeding has settled. Review FBC and iron studies if anaemic.

4–6 weeks

Re-assess fissure healing (if on topical GTN/diltiazem). Review haemorrhoid symptom control. Check compliance with stool softeners and lifestyle modification. Consider second-line therapy if inadequate response.

8–12 weeks

Decision point for fissure: if chronic fissure unresponsive to 8 weeks of topical therapy, refer to colorectal surgeon. Grade II–III haemorrhoids failing conservative management → specialist referral for banding or sclerotherapy.

3–6 months

Post-surgical follow-up: wound healing, recurrence assessment. Pelvic floor physiotherapy review for faecal incontinence. Reassess colonoscopy results and implement surveillance plans if polyps or malignancy identified.

12 months and beyond

Long-term surveillance: CRC surveillance colonoscopy per NHRMC/NBCSP guidelines. Annual review of continence management plan. Encourage ongoing fibre intake, adequate hydration, and regular bowel screening participation.

Special Populations

🤰 Pregnancy

Haemorrhoids: Extremely common in 2nd/3rd trimester due to progesterone-mediated venous dilation, increased intra-abdominal pressure, and constipation. Conservative management first-line (fibre, fluids, sitz baths). Avoid topical steroid preparations >7 days. Rubber band ligation is contraindicated in pregnancy.

Anal fissure: GTN 0.2% ointment — limited data in pregnancy but generally considered low risk for short courses; diltiazem 2% preferred by some practitioners. Sitz baths are safe and effective.

Perianal abscess: I&D is safe under local anaesthesia in pregnancy. Amoxicillin + clavulanate is safe; metronidazole traditionally avoided in 1st trimester (teratogenicity theoretical; Category B2). Clindamycin is an alternative.

Rectal bleeding: Always exclude placenta praevia (painless vaginal bleeding) and other obstetric causes before attributing to anorectal sources. Flexible sigmoidoscopy is considered safe in pregnancy; colonoscopy only if strongly indicated.

Avoid codeine and loperamide where possible (risk of neonatal respiratory depression, particularly in 3rd trimester and labour).

👶 Paediatrics

Anal fissure: The most common cause of rectal bleeding in infancy and childhood. Almost always associated with constipation. Treatment is dietary (fibre, fluids, fruit juice) plus stool softeners (macrogol 3350 is first-line in children >6 months).

Rectal prolapse: Self-limiting in >90% of children <3 years. Associated with constipation, diarrhoeal illness, cystic fibrosis (always screen), and malnutrition. Conservative management is first-line. Injection sclerotherapy or Thiersch suture for refractory cases.

Perianal abscess: More common in infants (males >females). May indicate underlying immunodeficiency if recurrent (e.g., leucocyte adhesion deficiency, chronic granulomatous disease). Simple I&D usually curative; antibiotics not required for most cases.

Haemorrhoids: Rare in children; always investigate for portal hypertension if present.

Always consider child abuse in the differential of perianal injury, bruising, or recurrent fissure in unusual locations. Refer to child protection services as per mandatory reporting obligations.

👴 Elderly (>65 years)

Rectal bleeding: Higher risk of serious pathology — diverticular bleeding, angiodysplasia, and CRC all increase with age. Lower threshold for colonoscopy referral.

Faecal incontinence: Prevalence up to 50% in residential aged care. Contributing factors include dementia, immobility, medications (laxatives, PPIs), faecal impaction with overflow, and reduced rectal compliance. Scheduled toileting programmes are effective.

Anticoagulants: Many elderly patients are on warfarin, DOACs (apixaban, rivaroxaban), or antiplatelets — these increase bleeding risk from any anorectal source. Check INR/anti-Xa levels before procedures. Do not stop anticoagulants without specialist advice for minor anorectal bleeding.

Surgical fitness: Rectal prolapse repair (perineal approaches — Delorme/Altemeier) preferred in frail elderly. Sacral nerve stimulation for faecal incontinence may be considered in selected patients.

Bowel cancer screening: NBCSP sends kits to ages 45–74. Encourage participation even beyond screening age if symptomatic. Polypharmacy review — assess for contributing medications.

🫘 Renal Impairment

Angiodysplasia: Higher prevalence in CKD patients (uraemic platelet dysfunction). Also exacerbated by anticoagulation during haemodialysis. Desmopressin (DDAVP) 0.3 μg IV may be used for acute bleeding episodes.

Constipation: Common due to phosphate binders (calcium carbonate, sevelamer), iron supplements, and reduced fluid intake. Macrogol 3350 is preferred (avoid magnesium-containing laxatives in CKD 4–5). Avoid sodium phosphate bowel preparations (risk of acute phosphate nephropathy).

Fistula-related sepsis: Dialysis patients with arteriovenous fistulas in the arm may have lower GI bleeding from vascular access-related complications. Consider this in the differential.

eGFR-based dose adjustments required for: amoxicillin + clavulanate (reduced doses in eGFR <30), metronidazole (accumulation of metabolites in severe renal impairment — reduce frequency). Ciprofloxacin requires dose reduction if eGFR <30.

🫁 Hepatic Impairment

Portal hypertensive colopathy: Patients with cirrhosis and portal hypertension may develop colonic angiodysplasia and haemorrhoids. Haemorrhoidal bleeding may be more severe due to coagulopathy and thrombocytopaenia. Avoid rectal procedures in decompensated cirrhosis without hepatologist input.

Coagulopathy: Deranged INR, low platelets, and reduced clotting factor synthesis increase bleeding risk. Correct coagulopathy before elective procedures. Vitamin K, FFP, or platelets as indicated.

Medications: Lactulose first-line for constipation in liver disease (also reduces hepatic encephalopathy risk). Avoid paracetamol doses >2 g/day in severe hepatic impairment. Metronidazole — use with caution (hepatotoxicity risk with prolonged use).

Refer to hepatologist if rectal bleeding is suspected to be related to portal hypertensive gastropathy or varices (upper GI source) rather than anorectal pathology.

🛡️ Immunocompromised

HIV/AIDS: Increased incidence of perianal abscess, fistula, condylomata, HSV ulcers, CMV colitis, and Kaposi sarcoma. Perianal disease may be the presenting feature of undiagnosed HIV. Low threshold for HIV testing in recurrent or atypical perianal sepsis.

Crohn's disease: Perianal fistula and abscess occur in 30–50% of Crohn's patients. Requires MRI pelvis, examination under anaesthesia (EUA), and multidisciplinary management (gastroenterologist + colorectal surgeon). Anti-TNF therapy (infliximab) is the mainstay of medical treatment for perianal Crohn's.

Transplant recipients / biologic therapy: Atypical infections, delayed wound healing, increased surgical risk. Conservative management where possible. Broad-spectrum antibiotics with Pseudomonas and fungal cover if severe sepsis.

CMV colitis should be considered in immunocompromised patients presenting with bloody diarrhoea. Faecal CMV PCR and colonoscopic biopsies are required for diagnosis. Ganciclovir or valganciclovir is the treatment of choice.

Aboriginal and Torres Strait Islander Health Considerations

Aboriginal and Torres Strait Islander Health

Aboriginal and Torres Strait Islander peoples experience a disproportionate burden of gastrointestinal disease, including higher rates of colorectal cancer (1.4 times the rate of non-Indigenous Australians), later-stage presentation, and significantly lower participation in the National Bowel Cancer Screening Program. Anorectal conditions such as haemorrhoids, fissures, and abscesses are also more prevalent in some communities, influenced by dietary factors (low fibre intake in remote communities with limited access to fresh produce), higher rates of chronic constipation, and delayed access to specialist care.

Screening participation

NBCSP participation rates for Aboriginal and Torres Strait Islander peoples remain approximately 25–30% lower than for non-Indigenous Australians. Culturally appropriate health promotion through Aboriginal Community Controlled Health Organisations (ACCHOs), Indigenous health workers, and community-led programs is essential to improve uptake.

Access to specialist care

Geographic isolation in remote and very remote communities (particularly in the Northern Territory, Western Australia, and Far North Queensland) means that access to colorectal surgeons, gastroenterologists, and endoscopy services is severely limited. Telehealth consultations and surgical outreach programs are critical. Median wait times for colonoscopy in remote areas may exceed 90 days compared with 30 days in metropolitan centres.

Diet and lifestyle factors

Many remote communities have limited access to affordable fresh fruit, vegetables, and high-fibre foods, contributing to chronic constipation and straining. The "Closing the Gap" nutrition initiatives and community store policies (e.g., Alice Springs "Good Food" program) aim to improve dietary quality but progress has been uneven.

Cultural and social considerations

Anorectal symptoms carry significant cultural shame and embarrassment in many Aboriginal and Torres Strait Islander communities, leading to delayed presentation. Same-sex healthcare providers may be preferred for sensitive examinations. Practitioners should use culturally safe communication, allow time for yarning, involve family and Elders where appropriate, and use interpreter services for patients whose primary language is not English (e.g., Yolŋu Matha, Kriol, Pitjantjatjara).

Chronic disease comorbidity

High rates of diabetes mellitus (3–4× higher than non-Indigenous Australians), chronic kidney disease, and obesity contribute to increased risk of surgical complications, impaired wound healing, and perianal sepsis. A holistic, multidisciplinary approach addressing comorbidities is essential. The RACGP's National Guide to a Preventive Health Assessment for Aboriginal and Torres Strait Islander People (3rd edition) provides comprehensive screening recommendations.

Community-level interventions

ACCHOs play a central role in bowel cancer awareness, FOBT kit distribution, and facilitating colonoscopy referrals. Integrated health promotion that links anorectal health with broader chronic disease management, sexual health, and men's/women's health programs is most effective. RHDAustralia provides guidelines relevant to perianal infections in settings where rheumatic heart disease and chronic streptococcal infections may complicate presentations.

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Practical recommendations for clinicians:

Proactively offer bowel cancer screening to all eligible Aboriginal and Torres Strait Islander patients aged 45–74, with culturally sensitive explanations of the iFOBT kit.
Use Aboriginal Health Practitioners and Indigenous health workers as intermediaries for discussing sensitive anorectal symptoms.
Prioritise same-day or expedited referral pathways for patients in remote communities who present with rectal bleeding, rather than watchful waiting that may result in loss to follow-up.
Ensure stool softeners and fibre supplements are available through community clinic pharmacies and remote area stores.
Advocate for improved endoscopy and surgical access through the Australian Government's Indigenous Australians Health Programme (IAHP).

Quick Reference — First-Line Management

Acute anal fissure

Fibre + sitz baths + GTN 0.2% or diltiazem 2% ointment

8 weeks

90% heal conservatively

Chronic anal fissure

Diltiazem 2% (preferred) ± botulinum toxin

8–12 weeks

Refer if no response — lateral sphincterotomy

Grade I–II haemorrhoids

Fibre + fluids + sitz baths ± Proctosedyl® 7 days

Ongoing

Rubber band ligation if Grade II persistent

Grade III–IV haemorrhoids

Surgical referral (haemorrhoidectomy / THD)

Variable

Grade IV = urgent surgical referral

Thrombosed external haemorrhoid

Excision under LA (<72 hrs) or conservative (>72 hrs)

Days

Paracetamol + ibuprofen for analgesia

Perianal abscess

Incision & drainage ± amoxicillin+clavulanate

5–7 days antibiotics if indicated

Antibiotics NOT needed if simple I&D, no cellulitis

Faecal incontinence

Pelvic floor physio + loperamide ± bowel programme

Ongoing

Endoanal USS + specialist referral if sphincter defect

Rectal bleeding + red flags

Urgent colonoscopy (<30 days)

As soon as possible

FBC, ferritin, iFOBT, calprotectin

📚 References

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12. Continence Foundation of Australia. Guidelines for the management of faecal incontinence. Melbourne: Continence Foundation of Australia; 2022. Available from: https://www.continence.org.au.
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