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Dr QM Leong
Dr QM Leong

Anal Fissures Vs Fistulas: Symptoms, Causes, And Treatment Options

Anal Fissures Vs Fistulas: Symptoms, Causes, And Treatment Options

Anal fissures and fistulas, while often confused, are distinct conditions that can cause significant discomfort and impact quality of life. Understanding the differences between these two is crucial for accurate diagnosis and effective treatment. 

With the rising incidence of gastrointestinal diseases globally, awareness and education about these conditions have become more important than ever. 

This article delves into the nuances of anal fissures and fistulas, backed by the latest research and medical insights, to provide a comprehensive understanding and guidance for those affected.

What Are Anal Fissures?

An anal fissure is a small tear in the thin, moist tissue lining the anus. Anal fissures are typically located at the posterior midline of the anus, which is the line running along the back side of the body. This is the most common location for such tears, although they can occasionally occur in other parts of the anal canal.

Acute cases can last less than six weeks, while chronic cases can last up to six weeks or longer.

Causes Of Anal Fissures

There are several possible causes for this condition, such as:

  • Passage of Hard or Large Stools: The most common cause of anal fissures is the tearing of the anal lining due to passing hard or large stools. This can happen during periods of constipation, where the stools are particularly firm and difficult to pass.
  • Chronic Diarrhoea: Repeated episodes of diarrhoea can also lead to fissures due to irritation and inflammation of the anal area.
  • Childbirth: Women may develop anal fissures as a result of childbirth, especially after a vaginal delivery with significant perineal tearing.
  • Anal Intercourse: This can cause physical trauma to the anal canal, leading to the development of fissures.

Risk Factors Of Anal Fissures

Anal fissures are common in both kids and adults, but occur more frequently for those with the following conditions:

  • Chronic Constipation: Individuals with chronic constipation are at an increased risk due to the frequent straining and passage of hard stools.
  • Inflammatory Bowel Diseases: Conditions like Crohn’s disease can predispose individuals to fissures due to inflammation and irregular bowel movements.
  • Ageing: Reduced blood flow and decreased elasticity in the anal area in older adults can increase the risk of fissures.
  • Other Factors: Reduced mobility, a low-fibre diet, and certain medications that cause constipation can also contribute to the risk.

Common Symptoms Of Anal Fissures

Patients who have anal fissures often suffer from a cycle of symptoms, including anal tear, pain during or after bowel movement, anal spasms, and constipation.

  • Anal Tear: The cycle often starts with a tear in the anal lining, typically caused by passing hard or large stools, chronic diarrhoea, or childbirth. The tear is usually small but can be quite painful.
  • Pain During and After Bowel Movements: One of the most common symptoms of an anal fissure is sharp, severe pain during and following bowel movements. This pain can be described as being similar to passing glass shards and can last for several hours after defecation.
  • Anal Spasm: The pain from the fissure can lead to involuntary spasms of the anal sphincter muscle. These spasms further aggravate the pain and can disrupt the normal blood flow to the anal lining, impeding the healing process.
  • Chronic Constipation: Due to the fear of pain during bowel movements, individuals may consciously or subconsciously begin to avoid defecation. This avoidance can lead to chronic constipation, as the stool stays longer in the colon and becomes harder and larger.
  • Recurring Anal Tear: The presence of hard, large stools due to constipation leads to the recurrence of the anal tear when these stools are eventually passed. This re-injury hinders the healing of the fissure and perpetuates the cycle.
  • Blood in Stool or Toilet Paper: Another common symptom is the presence of bright red blood in the stool or toilet paper, which is caused by the tear.
  • Itching or Irritation: Some individuals may also experience itching or irritation around the anus due to the fissure.

What Are Anal Fistulas?

An anal fistula, on the other hand, is an abnormal tunnel between the anal canal and the outer skin of the anus. It usually stems from an infection in the anal glands, which are located in the walls of the anal canal. 

Fistulas are classified based on their location and complexity. Simple fistulas typically have a single tract with one opening and are usually easier to treat. However, complex fistulas may have multiple tracts, multiple external openings, or involve a significant portion of the anal sphincter muscles. 

Causes Of Anal Fistula

The leading causes of an anal fistula are:

  • Untreated Anal Abscess: The most common cause of an anal fistula is an anal abscess that has not healed properly. An abscess forms when an anal gland becomes infected and filled with pus.
  • Infection: Bacterial, fungal, or viral infections in the anal area can lead to abscess formation, subsequently resulting in a fistula.

Risk Factors Of Anal Fistula 

Anal fistulas can develop in individuals from various backgrounds. But certain groups with the following conditions are at higher risk:

  • History of Anal Abscesses: A previous anal abscess significantly increases the risk of developing a fistula.
  • Gender and Age: While anal fistulas can occur in both men and women, they are more common in men. Japanese research found that the condition is most frequently diagnosed in adults aged between 30 and 40 years.
  • Inflammatory Bowel Diseases: Conditions like Crohn’s disease can increase the risk of abscesses and fistulas because of the chronic inflammation in the gastrointestinal tract.
  • Previous Anal Surgeries or Trauma: Surgical interventions or physical injuries in the anal area can predispose an individual to fistula formation.
  • Immunocompromised Conditions: Diseases like tuberculosis, HIV, or conditions requiring immunosuppressive therapy can increase susceptibility to infections, leading to abscesses and fistulas.

Common Symptoms Of Anal Fistulas

The symptoms of anal fistulas are similar to those of anal fissures. However, they vary in terms of severity and appearance. 

  • Pain: Pain associated with anal fistulas is often constant and throbbing. Unlike the acute pain of fissures, fistula pain does not necessarily correlate with bowel movements. It can be exacerbated by sitting, walking, or other movements and might not subside completely, even at rest.
  • Bleeding: Bleeding from a fistula can occur but is often less pronounced than in fissures. It is usually mixed with pus or a foul-smelling discharge when it does occur. This combination can indicate an ongoing infection or abscess drainage.
  • Discharge: A hallmark of anal fistulas is the presence of a discharge, which can be pus-like, bloody, or both. This discharge is often a key indicator of an ongoing or recurring infection and can lead to significant discomfort and irritation in the anal area. The discharge can also cause skin irritation, itching, and discomfort around the anus.

How Anal Fistula And Fissure Is Diagnosed?

Diagnosing an anal fistula and an anal fissure involves different procedures due to the nature of these conditions:

Anal Fistula Diagnosis

An anal fistula often requires more complex diagnostic tools as the fistula tract is not always visible externally and can have a complex path. These procedures include:

  • Physical Examination: The doctor usually starts with a careful examination of the anal area to look for openings of the fistula tract on the skin.
  • Anoscopy: A specialised instrument, an anoscope, may be used to inspect the inside of the anus and rectum.
  • Fistulography: This imaging test involves injecting a contrast dye into the fistula tract and taking X-ray images to delineate the fistula’s path.
  • Magnetic Resonance Imaging (MRI): MRI can be particularly useful in identifying the fistula’s route, especially in complex or recurring cases.
  • Ultrasound: An endoanal ultrasound might be used to get a clearer image of the fistula tract.
  • Exploratory Surgery: In some cases, surgery might be necessary to explore the area and determine the extent of the fistula.

Anal Fissure Diagnosis

An anal fissure is typically diagnosed through a physical examination due to its external visibility and characteristic symptoms. Diagnostic procedures include

  • Physical Examination: The most common method is a visual inspection of the anal area. The doctor looks for a visible tear in the skin around the anus.
  • Digital Rectal Exam (DRE): This involves inserting a lubricated, gloved finger into the rectum to search for any abnormality. However, this might not always be possible if there’s severe pain.
  • Anoscopy: Similar to a fistula diagnosis, an anoscope may be used for a closer look inside the anus and rectum, but this can be painful if a fissure is present.
  • Colonoscopy: If there’s suspicion of underlying conditions like Crohn’s disease or other bowel diseases, further tests, like colonoscopy, may be recommended.

Treatment Approaches For Anal Fistula And Fissures

The treatment options vary significantly between anal fissures and fistulas. They will depend on the severity and persistence of each condition.

Anal Fistula Treatments

The primary goals of anal fistula treatment are to heal the fistula tract while controlling any associated infection and to preserve the integrity and function of the anal sphincter muscles to prevent complications like incontinence. These treatments aim to ensure the patient’s comfort and minimise the risk of recurrence.

  • Surgical Drainage: Most anal fistulas require surgical treatment. The initial step often involves draining any abscesses.
  • Fistulotomy: The most common surgery for a fistula involves opening up the fistulous tract (fistulotomy) to allow it to heal from the inside out.
  • Seton Placement: In complex cases, a seton—a special thread—may be placed through the fistula to keep it open and allow it to drain over time.
  • Advanced Procedures: For more complex fistulas, especially those involving a significant portion of the anal sphincter, procedures like an advancement flap or a LIFT (ligation of intersphincteric fistula tract) procedure may be performed.

Anal Fissure Treatments

Treating an anal fissure involves several approaches aimed at relieving pain, reducing anal sphincter spasms, promoting healing, and preventing recurrence of chronic fissures. The treatment options are:

  • Home Remedies: Initial treatment often includes home remedies like warm sitz baths, increasing fibre intake, and staying hydrated to soften stools and reduce straining.
  • Topical Medications: Topical creams and ointments, such as nitroglycerin or topical calcium channel blockers, can be applied to relax the anal muscles and promote healing.
  • Botox Injections: In some cases, Botox injections are used to temporarily paralyse the anal sphincter muscle, reducing pain and aiding in healing.
  • Surgery: For severe or chronic anal fissures, a surgical intervention known as lateral internal sphincterotomy may be recommended to reduce pressure in the anal canal and promote healing.

Conclusion About Anal Fissure Vs Fistula

Anal fissures and fistulas, while both affecting the anal area, are distinct conditions requiring different treatments. Proper diagnosis is crucial for effective treatment, as it guides the appropriate management strategy. 

If you are experiencing the symptoms of either of these conditions, schedule an appointment at Advanced Colorectal and General Surgery. Our specialist, Dr QM Leong, has extensive experience in treating anal fissures and fistulas and is well-equipped to provide accurate diagnoses and tailored treatments. 

His expertise in advanced surgical techniques and comprehensive care ensures patients receive the most effective treatment for their condition, leading to relief and improved quality of life.

Frequently Asked Questions About Anal Fissure Vs Fistula

Can A Fissure Turn Into A Fistula?  

While rare, chronic or improperly healed fissures can potentially lead to fistula formation, particularly if an abscess develops.

How Can I Prevent Anal Fistula Or Anal Fissure?  

Maintaining a healthy diet rich in fibre, staying hydrated, and practising good bowel habits can reduce the risk of both fissures and fistulas.

How Long Does It Take To Recover From Treatments For These Conditions?

Recovery time is dependent on the severity of the condition and the type of treatment. Conservative treatments for fissures might lead to improvement within weeks, whereas recovery from surgery for fistulas can take longer.

Can These Conditions Recur After Treatment?

Recurrence is possible, especially if underlying issues like chronic constipation or inflammatory bowel disease are not managed effectively.