Anal Fissure

Gastroenterology (12%) Core Clinical Conditions

1B The Physician Associate is able to identify the condition as a possible diagnosis: may not have the knowledge/resources to confirm the diagnosis or to manage the condition safely, but can take measures to avoid immediate deterioration and refer appropriately.

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Definition Aetiology Pathophysiology Risk factor Sign and Symptoms Investigations Management

An anal fissure is a common medical condition that refers to a painful tear or crack in the lining of the anus. The anus is the opening at the end of the digestive tract through which waste is excreted from the body.

1. Trauma: The most common cause of anal fissures is trauma to the anal canal. The trauma can occur due to various factors such as passing hard or large stools, chronic constipation, or straining during bowel movements. These repetitive mechanical stresses on the delicate lining of the anus can lead to the formation of fissures over time.

2. Constipation: Chronic or recurrent constipation plays a significant role in the development of anal fissures. When constipated, the stools become harder and more difficult to pass. The straining required to expel these hardened stools can cause tears in the delicate anal lining, leading to fissures.

3. Diarrhoea: On the opposite end of the spectrum, persistent diarrhoea can also contribute to the development of anal fissures. Frequent liquid or loose stools can irritate the anal area, causing inflammation and weakening the anus' protective barrier. This vulnerability makes the anus more prone to developing fissures.

4. Anal Passage Obstruction: Conditions that obstruct the normal passage of faecal matter through the anus can increase the risk of developing fissures. Examples include an anal stricture (narrowing of the anal canal), anal stenosis (abnormal narrowing of the anus), or the presence of an anal abscess or haemorrhoids. These obstructions create added pressure during bowel movements, potentially leading to anal fissures.

5. Crohn's Disease: Crohn's disease, a chronic inflammatory bowel condition, can also predispose individuals to anal fissures. The inflammation and damage caused by Crohn's disease in the digestive tract can extend to the anus, making it more susceptible to fissure formation.

6. Childbirth: Women who have recently given birth may also experience anal fissures. The strain exerted during labour can lead to trauma in the anal region, resulting in fissures. Additionally, the hormonal changes that occur during pregnancy can affect the strength and elasticity of the anal tissue, making it more prone to tearing.

7. Anal intercourse: Engaging in anal intercourse can cause trauma to the lining of the anus and potentially result in the development of anal fissures. The friction and stretching involved in anal sex can tear the delicate anal tissue, leading to painful fissures.

1. Mechanical Trauma:

The primary underlying cause of anal fissures is mechanical trauma. This trauma can be caused by various factors, including large or hard stools, chronic diarrhoea, or prolonged straining during bowel movements. The constant stretching and tearing of the delicate anal lining result in the formation of a fissure.

2. Poor Blood Supply:

Another contributing factor to the pathophysiology of anal fissures is the compromised blood supply to the anal canal. The anal canal has a rich blood supply that ensures proper healing and maintenance of tissue integrity. However, repetitive trauma and pressure on the anal lining can lead to the formation of ischemic areas. Reduced blood flow to these areas hampers the healing process, contributing to the persistence and chronicity of anal fissures.

3. Internal Anal Sphincter Hypertonia:

The internal anal sphincter plays a vital role in maintaining continence and controlling the passage of stool. In individuals with anal fissures, there is often a hypertonicity or spasm of the internal anal sphincter muscles. This sphincter dysfunction results in increased pressure on the fissure, impeding its healing process, and causing pain during bowel movements.

4. Secondary Inflammation:

The presence of an anal fissure triggers an inflammatory response in the affected area. This inflammation further perpetuates the pain and discomfort associated with the condition. Additionally, the inflammatory process can lead to the release of chemical mediators, such as prostaglandins, which sensitise the nerve endings in the anal canal, exacerbating the pain experienced by individuals with anal fissures.

5. Chronicity and Persistence:

If left untreated or improperly managed, anal fissures can become chronic and persistent due to a vicious cycle of poor healing and repeated trauma. The persistent pain and discomfort associated with anal fissures can lead to a fear of defecation and subsequent withholding of stool. This, in turn, exacerbates constipation, leading to the passage of larger, harder stools, perpetuating the mechanical trauma and poor healing process.

See aetiology

1. Pain during bowel movements: One of the primary symptoms of an anal fissure is sharp, intense pain or discomfort during and after passing stools. This pain is often described as burning or cutting and can last for hours, making bowel movements a dreaded experience.
2. Rectal bleeding: Anal fissures frequently result in bright red blood on the surface of the stool or on the toilet paper after wiping. However, the bleeding is usually minimal and typically stops shortly after the bowel movement.
3. Itching and irritation: Many individuals with anal fissures experience itching and irritation around the anal region. This can be a result of the tear not healing properly and can lead to further discomfort and distress.
4. Visible tear or crack: In some cases, the anal fissure might be visible on examination. It can appear as a small tear, crack, or ulcer in the lining of the anus and can sometimes be accompanied by swelling or inflammation.
5. Constipation or difficulty passing stools: Chronic anal fissures can lead to a cycle of constipation and pain. Individuals may experience difficulty passing stools due to the fear of pain, resulting in further constipation and worsening of symptoms.
6. Muscle spasms: Painful spasms in the anal sphincter muscles, known as anal sphincter spasm, are commonly experienced by people with anal fissures. These spasms can intensify the pain and make it more difficult to heal.

Physical Examination:

During the physical examination, the PA will visually inspect the anal area for any visible signs of a fissure. They may use a gloved finger to gently examine the area for tenderness, muscle tone, and the presence of any possible underlying conditions, such as haemorrhoids. The examination can help rule out other possible causes of the symptoms.

History Taking:

The PA will also review the patient's medical history in order to gain a better understanding of their overall health and to identify any potential risk factors or contributing factors. This may include questions about previous incidents of anal fissures, past medical conditions, current medications, diet and lifestyle habits, and any relevant family history.

Colonoscopy: This procedure involves using a long, flexible tube with a camera to examine the rectum and colon. It can help rule out other causes of anal symptoms, such as inflammatory bowel disease or colorectal cancer.

Stool testing: FIT test or calprotectin.

1. Maintaining adequate personal hygiene: Keeping the anal area clean is crucial in preventing further irritation and infection. Gentle cleaning with warm water and mild soap after bowel movements is recommended. Avoid using harsh toilet paper or wipes that may aggravate the fissure.

2. Dietary modifications: Consuming a diet high in fibre can significantly help in managing anal fissures. Fibre softens stools, making them easier to pass, thus reducing strain on the fissure. Incorporating fruits, vegetables, whole grains, and legumes can promote regular bowel movements and prevent constipation.

3. Fluid intake: Hydration is essential to maintain regular bowel movements and prevent constipation, which can worsen anal fissures. Drinking an adequate amount of water throughout the day helps keep stool soft and promotes healthy digestion.

4. Topical ointments: Over-the-counter topical ointments or creams that contain analgesics or numbing agents can provide temporary relief from pain and discomfort associated with anal fissures. If the patient is in extreme pain a short course of lidocaine 5% ointment is often prescribed or glyceryl trinitrate (GTN) 0.4% ointment.

5. Stool softeners and laxatives: In some cases, where dietary modifications alone are not sufficient to relieve constipation, stool softeners or gentle laxatives can be prescribed to prevent straining during bowel movements, such movicol or lactulose.

6. Avoidance of irritants: It is crucial to avoid potential irritants that can worsen anal fissures. This includes spicy foods, caffeine, alcohol, and excessive consumption of dairy products. These substances may lead to increased bowel movements or diarrhoea, which can further irritate the fissure.

7. Surgical intervention: In severe cases or when conservative measures fail to achieve adequate healing, surgical intervention may be necessary.

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