Anal Fissures

Tears in the anal lining can cause pain and bleeding during bowel movements.

If bleeding persists, a colonoscopy is needed to rule out other causes

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What is an anal fissure?

An anal fissure is a small, shallow tear in the thin, delicate tissue (mucosa) that lines the anus. This tear often causes sharp pain and bleeding during or after bowel movements, making even routine bathroom visits distressing. Despite its small size, the discomfort it causes can be significant and long-lasting if not properly managed.

Anal fissures can occur in people of all ages, including infants, but are most commonly seen in young adults. The fissure usually forms as a result of trauma to the anal canal, often from passing hard or large stools, chronic constipation, or prolonged diarrhea. In some cases, excessive straining during bowel movements or even childbirth can also lead to fissure development.

There are two types of anal fissures:

Acute fissures — these are recent tears that typically heal within a few weeks with conservative management.

Chronic fissures — this type of anal fissure persists beyond six weeks and may be associated with a small skin tag (sentinel pile) or exposed internal sphincter muscle fibers, which often requires more targeted treatment.

Although anal fissures are a benign condition, they can cause intense discomfort and may recur if the underlying bowel habits are not addressed.

What causes anal fissure?

An anal fissure typically results from trauma to the anal canal, most often during the passage of hard or large stools. When the anal lining is overstretched, it can tear, especially if the tissue is already inflamed or fragile. While the initial cause is usually mechanical strain, several other factors may contribute to the development and persistence of fissures.

Common causes and contributing factors include:

Constipation and straining — one of the most frequent causes, constipation leads to hard, dry stools that stretch and injure the anal lining. Repeated straining during bowel movements worsens this risk.
Chronic diarrhea — frequent loose stools can irritate and inflame the anal area, creating a cycle of repeated minor injuries and delayed healing.
Anal trauma — this includes not only bowel-related injuries but also direct trauma from childbirth, anal intercourse, or insertion of foreign objects.
Tight anal sphincter muscles (hypertonicity) — some individuals naturally have increased resting pressure in the internal anal sphincter. This can reduce blood flow to the area, slowing healing and increasing the risk of fissure formation and recurrence.
Inflammatory conditions — diseases such as Crohn’s disease or ulcerative colitis can inflame the gastrointestinal tract, including the anal canal, which makes it more susceptible to tears.
Reduced blood flow — in older adults or people with poor circulation, decreased blood supply to the anal region can impair tissue repair, making fissures more likely to occur and harder to heal.

In many cases, a fissure may develop suddenly after a single episode of constipation or a particularly difficult bowel movement. However, for some, the condition becomes chronic when the internal anal muscles go into spasm, as it reduces blood flow and prevents healing.

If you are experiencing the symptoms,

consult a medical professional immediately.

Schedule an appointment with Dr Aaron Poh.

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What are the symptoms of anal fissures?

Anal fissures often present with distinct and uncomfortable symptoms that are hard to ignore. The hallmark symptom is sharp, intense pain during or just after a bowel movement, often described as a cutting or burning sensation. This pain may be severe enough to make individuals delay going to the toilet, which can worsen constipation and perpetuate the cycle of injury.

Key symptoms of anal fissures include:

Pain during bowel movements — a sudden, sharp pain that may persist for minutes to hours afterward is the most common and defining symptom. The discomfort may recur with each bowel movement.
Bright red bleeding — small amounts of fresh blood may be seen on the toilet paper or streaked on the surface of the stool. Unlike bleeding from deeper in the digestive tract, fissure-related bleeding is usually minimal and bright red.
Visible tear or crack — in some cases, a small tear in the skin around the anus can be seen, particularly if it has become chronic and is accompanied by a small skin tag (sentinel pile).
Spasm of the anal muscles — the internal anal sphincter may go into spasm, which not only causes pain but also restricts blood flow to the area, delaying healing.
Itching or irritation — ongoing irritation from the fissure can cause itching, especially when hygiene is difficult to maintain due to pain.

While the symptoms of anal fissures are often straightforward, they can resemble other anorectal conditions like hemorrhoids or abscesses.

What happens if a fissure is left untreated?

While many anal fissures heal on their own or with simple measures, untreated or chronic fissures can lead to complications that affect both comfort and quality of life. The longer a fissure remains unhealed, the higher the risk of persistent symptoms and structural changes to the anal canal.

Possible complications of anal fissures include:

Chronic fissure formation — if a fissure lasts more than 6–8 weeks, it is considered chronic. At this stage, the edges of the tear may thicken, and a sentinel skin tag (a small flap of skin) may develop at the outer edge. The internal anal sphincter may also become exposed, which further delays healing.
Anal muscle spasms — persistent pain can lead to continued spasm of the internal anal sphincter, which reduces blood flow to the area. This impaired circulation makes healing more difficult and increases the likelihood of recurrence.
Infection — though rare, a fissure can become secondarily infected, potentially leading to the formation of an abscess.
Bleeding and anemia — frequent rectal bleeding, even if small in amount, can lead to anemia over time in susceptible individuals.
Avoidance behaviors — the intense pain associated with bowel movements may cause individuals to avoid passing stools, which may worsen constipation and perpetuate the cycle of trauma and re-injury.

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Who is at risk of anal fissures in Singapore?

While anal fissures can affect anyone, certain individuals in Singapore are more likely to experience them due to physiological, lifestyle, or medical factors. Recognising these risk groups can help with early diagnosis and timely management.

Individuals with chronic constipation or diarrhoea — straining to pass hard stools or frequent loose motions can both damage the delicate lining of the anal canal, making fissures more likely to occur.
Pregnant women and postpartum mothers — hormonal changes, increased pelvic pressure, and the strain of childbirth, particularly vaginal delivery, can lead to constipation or direct trauma to the anal area, increasing fissure risk.
People with inflammatory bowel disease (IBD) — conditions such as Crohn’s disease and ulcerative colitis inflame the lining of the digestive tract, including the anus, which makes it more vulnerable to tearing.
Infants and young children — anal fissures are among the most common causes of rectal bleeding in young children, usually triggered by constipation and the passage of large stools.
Those who engage in receptive anal intercourse — without sufficient lubrication, anal intercourse can cause microtears or trauma to the anal lining, which may lead to fissure formation.
Individuals with a history of anal surgery or trauma — prior surgical procedures, injuries, or scarring around the anal region can weaken the tissue, making it more prone to fissures.
People with certain sexually transmitted infections (STIs) — infections like herpes or syphilis can cause ulcers or sores that increase the risk of fissures developing or worsening.
Older adults — with age, reduced blood flow to the anal region can impair healing and increase the risk of fissure development, especially when combined with constipation or reduced bowel motility.

What can I do to prevent anal fissures?

Preventing anal fissures largely comes down to maintaining regular, comfortable bowel habits and minimising strain on the anal area. Simple lifestyle changes can significantly reduce the risk of developing a fissure or experiencing a recurrence if you’ve had one before.

Keep your stools soft and regular — a high-fibre diet rich in fruits, vegetables, whole grains, and legumes helps prevent constipation. Drinking plenty of water, at least 1.5 to 2 litres daily, also keeps stools soft and easier to pass.
Avoid straining during bowel movements — don’t force or prolong toilet time. Respond to the urge to go promptly and try not to delay. Prolonged sitting or excessive straining increases pressure in the anal canal.
Practice good toilet habits — use the bathroom as soon as you feel the need. Avoid reading or using your phone for extended periods on the toilet, as this can worsen pressure on the anal area.
Stay physically active — regular exercise helps regulate bowel function and reduces the risk of constipation, especially in sedentary lifestyles.
Use gentle hygiene — clean the anal area gently with water after bowel movements. Avoid harsh soaps or excessive wiping, which can irritate the skin.
Manage chronic diarrhoea or constipation early — if you have frequent digestive issues, seek medical advice to identify and treat the underlying cause before complications like fissures develop.
Avoid trauma to the anal area — use appropriate lubrication during anal intercourse and avoid inserting any objects that could cause tearing.

How are anal fissures diagnosed?

Anal fissures are usually diagnosed through a simple physical examination and a review of your symptoms. In most cases, no complex testing is needed. Dr. Aaron Poh takes care to make the diagnostic process as comfortable as possible, ensuring accurate diagnosis and prompt relief without unnecessary discomfort.

Clinical history — the diagnosis begins with a discussion of your symptoms. Sharp pain during bowel movements, bright red bleeding, and a history of constipation or diarrhoea are strong indicators of a fissure.
Visual inspection — for many patients, the fissure can be seen with a careful external examination. In acute cases, the tear typically appears as a small crack in the skin near the anus. In chronic cases, features such as a sentinel pile (skin tag) or visible internal sphincter may also be present.
Digital rectal examination (DRE) — this may be done carefully, but in cases of severe pain, it is often avoided or delayed until the pain is under control. If performed, it helps rule out other conditions such as hemorrhoids, abscesses, or growths.
Anoscopy or proctoscopy — if needed, a small instrument may be used to examine the inside of the anal canal. This is more common in chronic or atypical cases, or when other causes of rectal bleeding need to be ruled out.

Most anal fissures are diagnosed on the spot during a clinic visit. If the symptoms or appearance are unusual, or if healing is delayed, further evaluation may be recommended to rule out conditions like Crohn’s disease, infections, or anal cancer.

What are the treatment options for anal fissures?

Treatment for anal fissures depends on whether the condition is acute (recent) or chronic (lasting more than 6 weeks). The goal is to relieve pain, promote healing, and prevent recurrence. Most acute fissures respond well to non-surgical approaches, while chronic fissures may require medical intervention.

Lifestyle and dietary adjustments

These are the common strategies for mild or acute fissures:

High-fibre diet — increasing fibre intake softens stool and reduces straining. Patients are encouraged to eat more fruits, vegetables, whole grains, and legumes.
Hydration — drinking adequate water helps maintain regular, soft bowel movements.
Bowel habit changes — avoiding straining, responding promptly to the urge to defecate, and not sitting too long on the toilet all help reduce pressure on the anal canal.

Medications and topical treatments

When fissures cause persistent pain or show signs of chronicity, targeted medical therapy may be prescribed:

Topical nitroglycerin or calcium channel blockers — these help relax the internal anal sphincter and improve blood flow, allowing the fissure to heal.
Topical anesthetics — lidocaine-based creams may be used to numb the area and reduce pain.
Stool softeners — these may be prescribed to ease bowel movements and avoid further trauma.

Warm sitz baths

Soaking the anal area in warm water for 10–15 minutes, especially after bowel movements, can help relax the sphincter, ease pain, and promote healing.

Botulinum toxin (Botox) injections

For chronic fissures that don’t respond to creams, Botox can be injected into the internal anal sphincter to temporarily paralyse the muscle, which helps reduce spasms and improves blood flow.

Surgical intervention

If all else fails, surgery may be recommended:

Lateral internal sphincterotomy (LIS) — this is the most effective surgical treatment for chronic fissures. It involves a small incision in the internal anal sphincter to reduce resting pressure and allow healing. It is typically done as a day procedure with a short recovery period.

Summary

Anal fissures are small but painful tears in the lining of the anal canal, often caused by the passage of hard stools, chronic constipation, or prolonged diarrhoea. Common symptoms include sharp pain during bowel movements, bright red bleeding, and a persistent feeling of discomfort or spasm. While most acute fissures heal with simple measures such as dietary changes, increased hydration, and topical creams, chronic fissures may require more targeted interventions like muscle-relaxing medications, Botox injections, or minor surgery.

If you are experiencing persistent anal pain or bleeding, schedule a consultation with us today for a detailed diagnosis and personalised treatment plan.

Frequently Asked Questions (FAQs)

Can anal fissures itch?

Yes, anal fissures can cause itching due to irritation and inflammation around the affected area.

Do anal fissures bleed?

Yes, it’s common to notice bright red blood on toilet paper or in the stool due to the tear in the anal lining.

Can anal fissures become infected?

While uncommon, if a fissure doesn’t heal properly, it can become infected, potentially leading to an abscess.

Are anal fissures a sign of cancer?

No, anal fissures are not indicative of cancer. However, persistent symptoms should be evaluated to rule out other conditions.

How long do anal fissures take to heal?

Acute fissures often heal within a few weeks with proper care, while chronic fissures may take longer and require medical intervention.

Can stress cause anal fissures?

Indirectly, stress can contribute to digestive issues like constipation or diarrhea, which may increase the risk of developing fissures.

Is it safe to exercise with an anal fissure?

Light to moderate exercise is generally safe and can aid digestion, but activities causing discomfort should be avoided until healing occurs.

Are over-the-counter creams effective for relieving anal fissure symptoms?

Yes, topical anesthetics or hydrocortisone creams can provide temporary relief, but it’s best to consult a healthcare provider for appropriate treatment.

Do I need to see a doctor for an anal fissure?

If symptoms persist beyond a few weeks or are severe, it’s important to consult a doctor for proper diagnosis and treatment.

Can diet impact anal fissure healing?

Absolutely. A high-fibre diet and adequate hydration can soften stools and promote healing of anal fissures.