Anal Fissure: Symptoms, Types, Causes and Treatment

Anal fissure is a common condition affecting people of all ages and backgrounds. Though often underestimated, its impact on daily life can be profound due to the pain and discomfort it causes. In this article, we’ll explore the symptoms, types, causes, and treatment options for anal fissure, drawing on the latest research and consensus guidelines to provide a comprehensive and practical overview.

Symptoms of Anal Fissure

Anal fissures may seem like a small problem, but they pack a big punch in terms of symptoms. Most people first notice sharp pain during or after bowel movements, often accompanied by bleeding or irritation. These symptoms not only cause physical discomfort but can also affect mental health and quality of life.

Symptom	Description	Prevalence/Notes	Sources
Pain	Severe, sharp, burning pain during and after defecation	Most prominent symptom	2 3 4 6 9
Bleeding	Bright red blood on stool or tissue	Common, often mild	3 6 7
Constipation	Hard stools, difficulty passing stool	Can be both a symptom and a cause	2 3 9
Pruritus	Anal itching	Less common	2 3
Sentinel tag	Small lump or skin tag near fissure	More common in chronic cases	2 6 8

Table 1: Key Symptoms

Pain: The Hallmark Symptom

Pain is the defining feature of an anal fissure. It is often described as severe, sharp, or burning, and usually occurs during bowel movements. Many people continue to experience pain for hours after a bowel movement, which can be so intense that it interferes with daily activities and sleep 2 3 4.

Bleeding

Bright red bleeding is frequently observed, either on the surface of the stool, on toilet paper, or in the toilet bowl. This is usually not profuse, but can be alarming to patients 3 6 7.

Constipation and its Vicious Cycle

Constipation is both a symptom and a contributing factor. The pain experienced during defecation often leads to stool withholding, which in turn makes stools harder and exacerbates the fissure, creating a vicious cycle 2 3 9.

Anal Pruritus and Discharge

Some people report itching (pruritus) or mucus-like anal discharge, but these are less common. When present, they may be signs of chronicity or secondary infection 2 3.

Chronic Changes: Sentinel Tag and Hypertrophied Papilla

Over time, chronic fissures may develop a sentinel skin tag—a small lump of tissue at the edge of the fissure—and/or a hypertrophied anal papilla just inside the anal canal. These changes can help differentiate chronic from acute fissures 2 6 8.

Types of Anal Fissure

Anal fissures are not all the same. Understanding their types helps guide diagnosis and management. The differences are primarily based on duration, location, and underlying causes.

Type	Features	Typical Location	Sources
Acute	Recent onset, superficial	Posterior midline	6 7 8 12 17
Chronic	Lasting >6 weeks, deeper, with secondary changes	Posterior midline, sometimes anterior	6 8 12 17
Primary	No underlying disease	Posterior/anterior	2 6 7 12
Secondary	Linked to other conditions	Lateral, multiple, atypical	6 7 12 17

Table 2: Types of Anal Fissure

Acute vs. Chronic Anal Fissure

• Acute fissures are recent tears, often appearing as a simple superficial split in the anoderm. They are more likely to heal with conservative measures 6 7 8 12.
• Chronic fissures persist for more than 6 weeks, tend to be deeper, and have visible secondary changes such as sentinel tags or exposed internal sphincter fibers. These are less likely to heal without more intensive treatment 6 8 12 17.

Primary vs. Secondary Fissure

• Primary fissures occur in otherwise healthy individuals, typically in the posterior or (less commonly) anterior midline of the anal canal 2 6 7 12.
• Secondary fissures are associated with other conditions such as Crohn's disease, infections (HIV, tuberculosis, syphilis), previous anal surgery, or malignancy. These are often lateral, multiple, or irregular in appearance and warrant further evaluation 6 7 12 17.

Causes of Anal Fissure

While the exact cause of anal fissures isn’t always clear, a combination of mechanical, physiological, and sometimes psychological factors are usually at play.

Cause	Mechanism/Explanation	Notes	Sources
Trauma	Overstretching of anal canal (e.g., hard stool)	Most common in primary fissures	1 6 9 12
Sphincter spasm	Increased resting pressure, reduced blood flow	Leads to chronicity	1 10 12 14 17
Constipation	Hard stool causes mucosal tears	Both cause and effect	2 3 9 12
Diarrhea	Frequent irritation/trauma	Less common	12
Underlying disease	IBD, infections, malignancy	Usually causes secondary fissures	6 7 12 17
Excessive cleansing	Irritation from hygiene habits	May induce fissures	11
Psychiatric Factors	Anxiety, stress	May contribute to onset or chronicity	3 5

Table 3: Main Causes

Mechanical Trauma and the Role of Stool

The majority of anal fissures are believed to result from trauma to the anal canal—most often due to the passage of hard or large stools, or from frequent episodes of diarrhea. The initial tear typically occurs in the posterior midline, likely due to anatomical vulnerabilities in blood supply 1 6 9 12.

Sphincter Spasm and Ischemia

A key factor in the persistence of fissures is increased resting pressure in the internal anal sphincter. This spasm reduces blood flow to the anoderm, making healing difficult and setting up a cycle of pain, sphincter spasm, and poor healing 1 10 12 14 17. Some recent evidence suggests the external sphincter may also play a role in certain patients 10.

The Vicious Cycle of Pain and Constipation

Pain during defecation encourages stool withholding, leading to harder stools and worsening trauma, which perpetuates the fissure 2 3 9 12.

Secondary Causes: When to Suspect More

Fissures that are off the midline, multiple, or persistent may signal underlying conditions like inflammatory bowel disease, infections (HIV, TB), or anal cancer. These require additional investigation and multidisciplinary management 6 7 12 17.

Behavioral and Psychological Contributors

Excessive cleaning or use of irritants can contribute to fissure development 11. Additionally, stress and psychiatric disorders such as anxiety and depression are often present in chronic cases, influencing both onset and severity 3 5.

Treatment of Anal Fissure

Treatment for anal fissure is aimed at breaking the cycle of pain, spasm, and poor healing. The choice of therapy depends on whether the fissure is acute or chronic and on the presence of underlying conditions.

Treatment	Approach/Description	Effectiveness/Role	Sources
Conservative	Fiber, sitz baths, stool softeners	First-line, acute cases	1 4 7 9 13 17
Topical therapies	GTN, diltiazem, nifedipine (CCBs)	Relax sphincter, heal fissure	4 13 14 15 16 17
Botulinum toxin	Injection into anal sphincter	For chronic/failed cases	13 14 15 16 17
Surgery	Lateral internal sphincterotomy (LIS)	Highest success for chronic	1 2 13 14 15 16 17
Addressing anxiety	Anti-anxiety meds, psychological support	Reduces pain, improves outcomes	3 5
Treat underlying disease	IBD, infection, malignancy	For secondary fissures	6 7 17

Table 4: Main Treatment Options

Conservative Management

Most acute fissures will heal with simple measures aimed at improving stool consistency and reducing trauma:

• Dietary fiber and hydration help prevent constipation.
• Sitz baths (warm water soaks) ease pain and promote relaxation of the sphincter.
• Topical anesthetics (like lidocaine) may provide symptomatic relief 1 4 7 9 13 17.

Topical Medications

When conservative therapy is insufficient, topical agents that relax the internal anal sphincter are used:

• Glyceryl trinitrate (GTN) ointment increases blood flow and promotes healing. However, headaches are a common side effect 13 14 15 16.
• Calcium channel blockers (diltiazem, nifedipine) are also effective and may have fewer side effects than GTN 13 14 15 16.
• Healing rates with medical therapy range from 50-90%, but recurrence is not uncommon 13 14 15 16.

Botulinum Toxin Injection

Botox injections into the anal sphincter temporarily paralyze the muscle, reduce spasm, and allow healing. Success rates are comparable to topical therapies, and the treatment can be repeated if necessary 13 14 15 16 17.

Surgery: Lateral Internal Sphincterotomy (LIS)

For chronic fissures unresponsive to medical therapy, LIS is the gold standard. The procedure involves a small cut in the internal sphincter to reduce resting pressure and improve blood flow.

• Success rates exceed 90% 1 2 13 14 15 16 17.
• Risks: Minor incontinence may occur in 3–4% of cases, but the risk is lower than previously thought 15 16.
• Open and closed techniques are equally effective 16 17.

Addressing Underlying and Contributing Factors

• Secondary fissures require specific treatment of the underlying condition (e.g., IBD, infection, malignancy) 6 7 17.
• Mental health: Addressing anxiety and depression with medications and counseling can improve pain and healing outcomes 3 5.

Special Cases

• Atypical fissures may require biopsy and multidisciplinary management 6 7 17.
• Patients with sphincter hypotonia (weak muscle) may benefit from advancement flaps rather than sphincterotomy 17.

Conclusion

Anal fissure is a painful but treatable condition. Understanding its symptoms, types, causes, and treatments is crucial for effective management and for reducing the impact on quality of life.

Key takeaways:

• Anal fissure most commonly presents with severe pain, especially during defecation, and sometimes with bleeding.
• Fissures can be acute or chronic, primary or secondary—recognizing the type is essential for proper management.
• Causes include mechanical trauma, sphincter spasm, constipation, and less commonly, underlying diseases.
• Treatment options range from conservative measures to topical medications, botulinum toxin, and surgery.
• Surgery (LIS) is the most effective treatment for chronic fissures, with a low risk of incontinence in carefully selected patients.
• Managing psychological factors and underlying diseases is important for comprehensive care.

With prompt recognition and appropriate therapy, most patients with anal fissure can achieve relief and restore their quality of life.