Anal Fissure

Anal fissure: symptoms, causes and treatment

Have you ever experienced a sharp pain during a bowel movement or noticed a bit of blood on the paper that made you wonder? An anal fissure, or a tear in the lining of the anus, is a common condition that can make daily life uncomfortable.

This page describes what an anal fissure is, the symptoms it causes and the treatment options that exist.

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What is an Anal Fissure? Definition of a Tear in the Anus

Imagine a small but deep wound in the delicate skin right at your anal opening. That is exactly what an anal fissure is. It is a tear, which typically occurs in the posterior (back) part of the opening.

Why does it hurt so much?

This is because the area is densely packed with nerve endings. When you have a bowel movement, the tear is stretched, and the pain can be intense and last long after the visit to the toilet.

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Causes of Anal Fissure: Why does the painful tear occur?

A frequently described contributing factor is the combination of hard stools, constipation, and straining during bowel movements. However, diarrhoea or repeated loose stools can also irritate the area and contribute to a tear.

Here are the typical culprits:

• Constipation: Hard and lumpy stools that require straining.
• Diarrhoea: Frequent, thin stools that irritate the mucous membrane.
• Excessive straining: Pushing too hard during bowel movements.
• Other factors: In rarer cases, it may be due to inflammation or underlying diseases, but most often it is a mechanical issue.

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Anal Fissure Symptoms: How do I know if I have a tear?

These are the primary anal fissure symptoms:

• Intense pain during and after bowel movements: The pain can last from a few minutes to several hours.
• Fresh, bright red blood on the toilet paper or in the toilet bowl: Pay attention to the colour; darker blood may indicate other issues.
• Itching and discomfort: Especially if the fissure is chronic.
• A visible skin tag or small lump: In some cases, a chronic anal fissure can develop a small external skin tag (sentinel pile) or an internal polyp-like growth.

How is an Anal Fissure treated? - Treatment options

An anal fissure can be acute or chronic, and this affects both the course and the treatment. In both cases the aim is to relieve pain and muscle spasm and support healing of the tear. What is relevant for the individual is decided by the doctor together with the patient.

With an acute anal fissure

The ASCRS 2023 guideline describes non-operative treatment as the typical initial management of an acute fissure. The guideline applies to acute fissures and does not describe the same for chronic fissure.

Among the measures the guideline mentions are soft, regular stools with fibre-rich food and sufficient fluid, fibre supplements or mild laxatives, and sitz baths. These are possible, individually relevant measures, not a fixed plan; the need, form and duration are assessed medically. Some patients experience a warm sitz bath as relieving, but it is not documented to relax the sphincter muscle.

With a chronic anal fissure

For a chronic fissure there are several possible treatments. They do not follow a fixed order, and the choice is a medical assessment based on symptoms, examination findings, sphincter function, treatment already tried and the individual risk of faecal incontinence.

• Local anaesthetic ointment (e.g. lidocaine) may be used for symptom relief.
• Nitroglycerin ointment is approved in Denmark for relief of pain from chronic anal fissure. The ASCRS notes that it often causes headache, which can limit its use.
• Diltiazem cream does not exist as a finished medicinal product with a Danish marketing authorisation for anal fissure. It is a pharmacy-compounded (magistral) preparation, made at the pharmacy for the individual patient on prescription. That is different from using an authorised product outside its approved indication. The ASCRS reports comparable efficacy to nitroglycerin but fewer cases of headache; local skin irritation can occur with either agent.
• Botulinum toxin (Botox) injected into the internal sphincter temporarily relaxes the muscle. The effect is temporary, its duration varies, and recurrence occurs. In a pooled analysis referenced by the ASCRS covering around 1,500 patients, healing rates ranged from 33% to 96% across differing studies, and transient faecal incontinence was reported in around 5%.
• Lateral internal sphincterotomy (LIS) is an operation in which the surgeon divides part of the internal sphincter muscle so that muscle tension is reduced. The ASCRS states healing rates of 88-100% and faecal incontinence in 8-30% as guideline-reported ranges across studies with varying follow-up and reporting methods.

The percentages above apply to the study populations examined and are not a prognosis for the individual patient. The choice of product, strength, duration and any procedure follows a conversation about contraindications, side effects and alternatives.

Why is it important to seek help?

Although an anal fissure is rarely dangerous, it can significantly reduce your quality of life. The constant pain and fear of toilet visits can lead to stress and isolation. An anal fissure that is not examined or treated can in some cases become chronic, which typically requires more treatment than an acute fissure.

Contact your doctor if you experience symptoms of an anal fissure, so that together you can assess what is relevant in your situation.

Sources

1. Davids JS, Hawkins AT, Bhama AR, Feinberg AE, Grieco MJ, Lightner AL, Feingold DL, Paquette IM. The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Management of Anal Fissures. Dis Colon Rectum. 2023;66(2):190-199. Clinical practice guideline based on a systematic literature review and expert consensus from ASCRS; covers conservative, pharmacological and surgical treatment of acute and chronic anal fissure in adults. The percentages and grades of recommendation come from the guideline's own source studies and should not be read as a prognosis for an individual patient.