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Dr Sulaiman YusofColorectal Surgery

Anal and perianal

Anal fissure treatment. A small tear. A disproportionate amount of pain.

Even a minor fissure can cause pain that feels disproportionate to its size, particularly during and after a bowel movement. Most heal without surgery when treated early.

Anatomical cross-section of the anal canal, opened to show the lining. At the lower end, where the canal meets the skin, a small red split runs down the midline of the otherwise smooth pink lining.
The tear itself is small. Even so, it exposes underlying muscle and nerve tissue, which is why even a minor fissure can hurt out of proportion to its size.
1 · The teara small split at the midline
2 · The sphincterthe muscle that goes into spasm
3 · The liningwhere the tear starts
  1. A tear at the midline
  2. Spasm stops it healing
  3. Six weeks decides
  4. Ointment first, surgery last

In short

50

Per cent

Of acute fissures heal with conservative measures alone, and more when symptoms are under a month old.

6

Weeks

Past this a fissure is chronic, which changes both the treatment and the timeline.

2-4

Days

Most desk-based patients are back at work this soon after sphincterotomy.

No

Referral

You do not need a referral. Same-day and same-week appointments are available.

The surgeon

Dr Sulaiman Bin Yusof

Senior Consultant Colorectal and General Surgeon, seeing patients at five clinics in Singapore.

  • MBChB (Sheffield), M.Med (Surgery), FRCSEd (General Surgery)
  • Consults in English and Malay
  • MOH Fellowship, Peter MacCallum Cancer Centre, Melbourne
  • Singapore Health Quality Service Star Award 2023
  • Dean's Honour Roll for Teaching

Five clinics across Singapore

  • ORCHARD / NAPIER

    Gleneagles Medical Centre

    6 Napier Road #06-16, Singapore 258499

  • NOVENA

    Mount Elizabeth Novena

    38 Irrawaddy Road, #10-48/49, Singapore 329563

  • JOO CHIAT / EAST COAST

    Parkway East Hospital

    #05-08, 319 Joo Chiat Place, Singapore 427989

  • THOMSON

    Mount Alvernia Hospital

    #08-62, Medical Centre D, 820 Thomson Road, Singapore 574623

  • FARRER PARK

    Farrer Park Medical Centre

    #14-12, 1 Farrer Park Station Road, Singapore 217562

01

When to act

When to see a doctor

Important: Rectal bleeding should always be assessed by a doctor, even when the cause seems obvious. Anal fissures and colorectal cancer can produce similar symptoms. If you are over 50, have a family history of bowel cancer, or notice any change in your bowel habit alongside the bleeding, a colonoscopy should be considered to ensure nothing more serious is missed.

  • Pain with bowel movements lasting more than two to three weeks despite conservative measures
  • Rectal bleeding that is unexplained, heavier than expected, or accompanied by any change in bowel habit
  • Known history of Crohn's disease with new anal symptoms
  • A lump near the anus that does not resolve
  • Conservative measures have not improved symptoms within four weeks
Weeks 2 to 3pain despite conservative measures
Week 4no improvement on conservative measures
Week 6the fissure is chronic

Dr Sulaiman's perspective

Patients often delay seeking help because the condition feels embarrassing to discuss. My advice is always: come early. Assessment is straightforward, treatment starts quickly, and the sooner we begin, the less likely a simple acute fissure becomes a chronic problem requiring surgery.

02

The six-week line

Acute and chronic, and why it decides treatment

Acute fissures are tears present for fewer than six weeks. The tissue is fresh, the edges are clean.

Chronic fissures have been present for more than six weeks, or keep recurring. Over time, the base of the tear develops exposed fibres of the internal anal sphincter, the edges become thickened and scarred, and a small external lump, called a sentinel pile or sentinel skin tag, often forms at the lower edge.

The reason chronic fissures resist healing is a self-perpetuating cycle: the internal anal sphincter goes into persistent spasm, which reduces blood flow to the area, which prevents healing, which perpetuates the pain and spasm. Breaking this cycle is the goal of treatment.

If you have had pain with bowel movements for more than six weeks, or your symptoms have improved and returned more than once, your fissure is likely chronic. This changes both the treatment approach and the timeline for recovery.

03

The options

Anal fissure treatment, from ointment to surgery

Treatment is stepped. The approach starts with the least invasive measures and escalates based on response.

  1. Step 1

    Conservative measures

  2. Step 2

    Topical treatment

  3. Step 3

    Botox injection

  4. Step 4

    Surgery

Published healing rates quoted on this page

Conservative measures, acute fissureapproximately 50%
GTN 0.2% ointmentapproximately 50%
Diltiazem 2% creamaround 68%
Nifedipine 0.3% cream70 to 90%
Botox injection, initial60 to 80%
Lateral internal sphincterotomy88% or higher
Tailored sphincterotomy95% or higher
Anocutaneous advancement flapat least 81%
Published series, as quoted in the sections below. The papers are listed in the evidence disclosure.

Conservative measures

Addressing the underlying cause is essential before any medication. If constipation is driving the fissure, no topical cream achieves lasting healing without first normalising stool consistency.

  • High-fibre diet
  • Adequate hydration
  • Stool softeners
  • Sitz baths
  • Avoid straining and prolonged toilet sitting

Topical treatment

Topical agents work by reducing internal anal sphincter spasm, breaking the ischaemia cycle that prevents healing.

Dr Sulaiman's perspective

GTN ointment is my mainstay of topical treatment. I review patients at two weeks to assess early healing and tolerance. Around 50 to 60% of patients show meaningful improvement with GTN over a full treatment course. For those who do not improve, or where the fissure is chronic from the outset, I move to the next step promptly rather than prolonging the same treatment indefinitely.

Botox injection

For fissures that have not responded adequately to topical treatment, or for patients presenting with a chronic fissure where topical treatment alone is unlikely to succeed, a Botox injection into the internal anal sphincter is an effective next step.

The procedure is performed as a day case, typically under a short general anaesthetic to ensure accurate placement. Most patients find their pain improves significantly within one to two weeks.

Dr Sulaiman's perspective

I particularly favour Botox over surgery as a first interventional step in women. The reason is anatomical: women have shorter anal sphincters than men, which means that any surgical division of the sphincter carries relatively greater functional consequence. Botox achieves temporary sphincter relaxation without any permanent structural change, which makes it my preferred choice in women with chronic fissures, or in any patient where sphincter strength is a concern.

In men with a chronic or recurrent fissure that has not responded to Botox, I would typically recommend proceeding to LIS.

Lateral internal sphincterotomy (LIS)

LIS is the gold-standard surgical procedure for chronic and recurrent anal fissures, with published healing rates of 88% or higher.

A small, precise incision is made in the lower portion of the internal anal sphincter. This permanently reduces resting sphincter pressure, eliminates chronic spasm, and restores blood flow to the fissure, allowing it to heal. The procedure is performed as day surgery under general anaesthesia and takes less than 30 minutes.

Dr Sulaiman's perspective

LIS is the most reliable long-term treatment for patients with recurrent or chronic fissures. In my practice, I perform a tailored sphincterotomy to the apex of the fissure rather than a fixed length. In women, this corresponds to division of less than 25% of total sphincter length (typically under 8mm).

The concern patients most commonly raise is incontinence, and it is one I take seriously and discuss openly before every procedure.

For patients where I have any concern about baseline sphincter function, a history of obstetric injury, previous anorectal surgery, or known Crohn's disease, I will either recommend Botox or advancement flap as the preferred surgical option, or arrange anorectal manometry to formally assess sphincter function before proceeding.

Risk disclosure: LIS carries a small but real risk of faecal incontinence. Older pooled analyses put overall rates at 8 to 11%; the largest analysis of randomized trials (Nelson et al., Techniques in Coloproctology, 2017 (source: Nelson and colleagues, Techniques in Coloproctology, 2017, opens in a new tab)) reports 3.4 to 4.4%. This risk is higher in women, patients with a history of obstetric injury, those with pre-existing sphincter weakness, and patients with Crohn's disease. Dr Sulaiman will discuss your individual risk profile at consultation before recommending any surgical procedure.

Anocutaneous advancement flap

For patients at higher risk of incontinence after LIS, an anocutaneous advancement flap is a sphincter-preserving alternative.

A small flap of healthy perianal skin is advanced to cover the fissure after excision, promoting healing without dividing the sphincter. Published healing rates are at least 81%, with fecal incontinence rates of only 0 to 6% (typically 2 to 2.5%), significantly lower than LIS.

Fissurectomy

In selected cases, particularly where there is extensive surrounding scar tissue, a large sentinel skin tag, or a chronic fissure in a patient not suitable for LIS, fissurectomy is performed. This involves surgically removing the fissure and any associated scarred or unhealthy tissue, creating a clean wound that heals fresh. It is sometimes combined with a partial sphincterotomy or advancement flap depending on operative findings.

04

What it is

What an anal fissure is

Most anal fissures are entirely treatable. Approximately half of acute cases heal with conservative measures within a few weeks. When they do not, effective medical and surgical options exist, and with the right treatment at the right time, outcomes are consistently good.

05

What you are feeling

What an anal fissure feels like

The symptom pattern of an anal fissure is distinctive:

Sharp pain during bowel movements

most patients describe a cutting, tearing, or burning sensation at the moment of passing stool.

Bright red blood on toilet paper or the surface of stools

usually small in volume but vivid in colour. Blood mixed into the stool, or a darker colour, warrants further investigation to rule out other sources.

Itching or irritation around the anus

particularly as the fissure edges dry or become inflamed between episodes.

A small lump near the anus

if present, this sentinel skin tag indicates the fissure has become chronic.

06

Where it starts

What causes an anal fissure

Several factors can cause a tear in the anal canal lining:

Constipation and hard stools

The most common cause. Hard stools stretch the anal canal beyond its normal capacity, causing a tear in the lining.

Straining

Repeated straining increases pressure on the anal lining with each bowel movement, making tears more likely.

Prolonged diarrhoea

Repeated passage of loose stools irritates the lining and prevents recovery between episodes.

Childbirth

The pressure and stretching of vaginal delivery is a recognised cause, particularly following prolonged labour.

Inflammatory bowel disease

Conditions such as Crohn's disease weaken the anal lining chronically. Fissures in Crohn's patients often behave differently from standard fissures and require a tailored treatment approach.

07

Confirming it

How an anal fissure is diagnosed

Diagnosis is clinical and does not require complex investigations in most cases.

History and symptom review

The pattern of pain during and after bowel movements, alongside any history of constipation, diarrhoea, or childbirth, gives a strong indication before any examination takes place.

External inspection

In most cases the fissure is visible externally as a tear at the posterior midline of the anus (the 6 o'clock position). The presence of a sentinel skin tag confirms chronicity.

Anoscopy

If the fissure is not externally visible, a small lighted instrument is used to examine the lower anal canal.

Illustration of a short, lighted examination scope placed just inside the anal canal, with a circular inset showing the smooth inner lining as the doctor sees it.
Anoscopy uses a small lighted instrument to examine the lower anal canal gently, without a full rectal examination.
08

Staying clear of it

Preventing another anal fissure

A fissure that has healed can return if the underlying risk factors are not addressed. The most important long-term habits:

Maintain a high-fibre diet consistently, not only during episodes

Stay well hydrated

Do not strain and do not sit on the toilet longer than needed

Address constipation early, do not wait for a tear to develop

If early symptoms return, restart conservative measures immediately rather than waiting

09

Paying for it

Anal fissure surgery cost in Singapore, MediSave and insurance

Surgical treatment of anal fissures, including LIS and fissurectomy, is a MediSave-claimable procedure under the Ministry of Health’s Table of Surgical Procedures. Most Integrated Shield Plans provide coverage for these procedures performed as day surgery at private hospitals. The figures below are MOH’s own, so you can see the range before you ask us for a written estimate.

Anal fissure surgery cost in Singapore

MediSave can cover, up toThe $1,120 operation limit under Table 2B, plus up to a further $830 a day of day-surgery charges.
$1,950
MOH surgeon fee benchmarkLateral internal sphincterotomy or fissure excision, TOSP SF831A.
$2,100 to $3,400
Anaesthetist fee benchmark
$700 to $1,000
Typical total bill, day surgeryMOH's median of bills actually paid at private hospitals in 2023. Half of patients paid between $5,568 and $7,325.
$6,229

Most fissures are treated without an operation, so these figures apply only to the minority who need surgery after conservative treatment has not worked. Benchmarks are MOH's recommended ranges before GST; the bill is what patients were actually billed, GST included. The figure that applies to you is the written fee estimate the clinic gives you before the date is set.

Source: CPF Board, using MediSave for hospitalisation (source: CPF Board, using MediSave for hospitalisation, opens in a new tab). Withdrawal limits by TOSP table: MOH, MediSave withdrawal limits (source: Ministry of Health, MediSave withdrawal limits, opens in a new tab). Table classification: MOH, Table of Surgical Procedures, 1 June 2026 (source: Ministry of Health, Singapore, Table of Surgical Procedures, updated 1 June 2026, opens in a new tab). Fees and bills: MOH bill information for TOSP SF831A (source: Ministry of Health, Singapore, fee benchmarks and bill information for SF831A, opens in a new tab), transacted bills 1 January to 31 December 2023.

MediSave

up to $1,950

Typical total bill, day surgery: $6,229.

10

Common questions

Questions about anal fissures.

Can an anal fissure heal on its own?
Yes, approximately 50% of acute fissures (present for fewer than six weeks) heal with conservative measures: dietary changes, stool softeners, sitz baths, and topical creams, with higher success rates when symptoms have been present for less than one month. Chronic fissures, present for more than six weeks or recurring repeatedly, are much less likely to heal without medical or surgical intervention.
What can I do at home to help an anal fissure heal?
  • High-fibre diet: Aim for 25 to 35g of dietary fibre daily through fruits, vegetables, and wholegrains. Soluble fibre (oats, psyllium husk) is particularly effective.
  • Adequate hydration: At least 1.5 to 2 litres of fluid daily.
  • Stool softeners: Lactulose or macrogol (Movicol) can be used short-term while dietary changes take effect.
  • Sitz baths: Soaking the anal area in warm water for 10 to 15 minutes two to three times daily relaxes sphincter spasm and improves local blood flow.
  • Avoid straining and prolonged toilet sitting: Both increase anal canal pressure and delay healing.
Why does the pain last for hours after a bowel movement?
The pain peaks during the movement and typically continues as a dull ache or spasm for 30 minutes to several hours afterwards. This delayed spasm is caused by the internal anal sphincter contracting in response to the tear.
Will the examination hurt?

This is performed gently and avoids the discomfort of a full rectal examination, which can be very painful in acute cases with significant spasm.

If your pain is severe, a full internal examination may not be possible at the first visit. This is normal and does not prevent a diagnosis or the start of treatment. A thorough examination under anaesthesia can be arranged at the time of any surgical procedure if needed.

Which ointment is used for an anal fissure, and what are the side effects?

Glyceryl trinitrate (GTN) 0.2% ointment: Applied to the anal canal twice to three times daily, GTN releases nitric oxide which relaxes the internal sphincter and improves blood flow. Healing rates approximately 50%. Main side effect is headache (30% of patients).

Diltiazem 2% cream: A calcium channel blocker with comparable efficacy to GTN (healing rates around 68%) with significantly lower headache rates, a useful alternative for patients who do not tolerate GTN.

Nifedipine 0.3% cream: Another calcium channel blocker showing healing rates of 70 to 90% in recent studies. A 2025 network meta-analysis (source: Wang and colleagues, International Journal of Surgery, 2025, opens in a new tab) found nifedipine may have the highest healing rate among topical agents.

If GTN headaches are a problem, diltiazem cream is a practical alternative with similar efficacy. Where available, nifedipine is another excellent option with potentially higher healing rates.

How long does Botox for an anal fissure last?

Botox temporarily paralyses the sphincter muscle, eliminating the chronic spasm that prevents healing. Initial healing rates are 60 to 80%, though long-term sustained healing is lower (around 30 to 45% at three years; Arroyo et al. 2005 (source: Arroyo and colleagues, International Journal of Colorectal Disease, 2005, opens in a new tab), Lin et al. 2016 (source: Lin and colleagues, Diseases of the Colon and Rectum, 2016, opens in a new tab)) compared to surgery, and recurrence occurs in up to 42% of patients. Despite this, Botox remains valuable as it avoids permanent structural change and can be repeated if needed.

Patients should understand that while Botox is effective, long-term sustained healing is lower than with surgery, and some patients may require repeat treatment or eventually proceed to surgery.

How long does an anal fissure take to heal?
Acute fissures typically heal within four to six weeks with proper treatment. Chronic fissures take longer, expect eight to twelve weeks with medical treatment, and four to six weeks of progressive improvement following surgery. Surgical wound healing after LIS usually completes within four to six weeks.
What is a tailored sphincterotomy?
Modern evidence supports a tailored approach, limiting the sphincterotomy to the apex of the fissure rather than extending it to the dentate line. Three randomized trials totalling 259 patients demonstrated healing rates of 95% or higher.
Is fissure surgery painful?
The procedure is performed under general anaesthesia. You will feel nothing during it. Post-operative discomfort is usually mild and manageable with standard oral analgesia. Most patients are surprised by how well-tolerated the recovery is. Bowel movements in the first week can be tender, which is why stool softeners are prescribed as standard post-operatively.
How soon can I go back to work?
Most patients with desk-based jobs return within two to four days. Jobs involving heavy lifting, prolonged standing, or physical labour should be avoided for two to three weeks.
Will sphincterotomy affect my bowel control?
Yes, and this is something Dr Sulaiman discusses honestly with every patient before surgery. Older pooled analyses put overall postoperative incontinence after LIS at 8 to 11%; the largest analysis of randomized trials (Nelson et al., Techniques in Coloproctology, 2017 (source: Nelson and colleagues, Techniques in Coloproctology, 2017, opens in a new tab)) reports 3.4 to 4.4%. Reported rates of difficulty controlling wind range from 5 to 25%, with stool urgency less common. With tailored sphincterotomy, incontinence rates are significantly lower (2% versus 11% with conventional technique). Permanent significant incontinence is rare in carefully selected patients. Patients with obstetric injury history, Crohn's disease, or previous anal surgery carry higher individual risk and are assessed individually.
Can a fissure come back after surgery?
Recurrence after LIS is low, typically 3 to 6% in published series. This compares favorably to Botox injection, which has recurrence rates of 28 to 42%. Recurrence is more likely if the underlying cause (constipation, straining habits, low fibre intake) is not addressed after surgery.
Can an anal fissure turn into cancer?
No. Anal fissures are benign tears and do not cause or increase the risk of cancer. However, rectal bleeding, even when a fissure is present, should always be properly assessed, because other conditions including colorectal cancer can produce similar symptoms. If you are over 50, or if your symptoms are not fully explained by the fissure, a colonoscopy may be recommended.
Is anal fissure surgery claimable under MediSave?
Yes. Surgical treatment of anal fissures (LIS and fissurectomy) is claimable under MediSave at the prevailing MOH withdrawal limits for day surgery procedures. Most Integrated Shield Plans also cover these procedures. Contact our clinic for guidance on your specific plan.
What is the difference between a fissure, a fistula and piles?
Three distinct conditions affecting the same region, frequently confused. A fissure is a tear in the anal lining. A fistula is an abnormal tunnel between the anal canal and the skin around the anus, usually arising from a previous abscess. A pile (haemorrhoid) is a swollen vascular cushion in the anal canal. All three can cause bleeding and discomfort. Treatment is entirely different for each, which is why a proper examination and diagnosis matters.

Evidence disclosure

Evidence Disclosure: Clinical information on this page reflects Dr Sulaiman's practice and is informed by published evidence including: 2023 ASCRS Clinical Practice Guidelines for Anal Fissure (Davids et al.) (PubMed record, opens in a new tab); 2021 ACG Guidelines on Benign Anorectal Disorders (Wald et al.) (PubMed record, opens in a new tab); 2025 network meta-analysis on topical agents (Wang et al.) (PubMed record, opens in a new tab); 2024 meta-analysis on Botox vs LIS (Bonyad et al.) (PubMed record, opens in a new tab); 2022 network meta-analysis on anal fissure treatments (Jin et al.) (PubMed record, opens in a new tab); 2017 analysis of LIS outcomes across 148 randomized trials (Nelson et al., Techniques in Coloproctology) (PubMed record, opens in a new tab); long-term Botox healing follow-up data (Arroyo et al. 2005 (PubMed record, opens in a new tab); Lin et al. 2016 (PubMed record, opens in a new tab)); systematic review data on tailored sphincterotomy outcomes (healing 95% or higher, incontinence 2% versus 11% with conventional technique); prospective data on safe division limits in women (under 8mm, under 25% sphincter length).

11

Get it looked at

Pain with every bowel movement for more than six weeks? Come early.

Consult Dr Sulaiman for an assessment and a personalised treatment plan. Book a consultation with Dr Sulaiman today. Same-day and same-week appointments available.