Anal fissure – what to do?

Anal fissure – what to do? Causes and development simply explained

An anal fissure is a longitudinal tear of the mucosa in the anal canal area, usually a few millimeters to a maximum of two centimeters long. Medically, it is a painful lesion of the anodermal epithelium, typically located in the posterior midline, less commonly anterior. The injury affects the sensitive zone below the dentate line, an area with a high nerve density. Therefore, even small defects can cause severe pain. An anal fissure is a painful mucosal injury in the anal canal, usually caused by mechanical overstretching due to hard stools. A key factor in its development and chronicity is increased sphincter muscle tone, which leads to impaired blood flow. Early treatment therefore aims not only at wound healing but also at reducing pressure and regulating stool.

Anatomy of the anal canal – why is the mucosa so sensitive?

The anal canal is lined with sensitive mucosa that is exposed to mechanical stress from stool passage. If this mucosa is overstretched or injured, a tear can occur. The interplay between the following is crucial:

• Stool consistency
• Pressure in the anal canal
• Tension of the internal sphincter muscle (musculus sphincter ani internus)

How does an anal fissure develop? Common causes and risk factors

The most common cause is hard, dry stool due to constipation. Straining increases pressure, overstretching the sensitive mucosa. This leads to mechanical injury.

• Typical triggering factors are:
• Chronic constipation
• Straining hard during bowel movements
• Diarrhea with frequent bowel movements
• Childbirth (mechanical stress)
• Anal intercourse
• Inflammatory bowel diseases (e.g., Crohn's disease)
• Pre-existing proctological conditions such as hemorrhoids.

Why does an anal fissure sometimes not heal? The pain-spasm cycle

A characteristic feature of the pathophysiology is a pain-spasm-ischemia cycle.

• The mucosal tear causes severe pain.
• The internal sphincter then reflexively spasms.
• Increased muscle tone reduces local blood flow.
• Reduced perfusion delays wound healing.
• The fissure persists or becomes chronic.

If this cycle persists, an acute anal fissure can develop into a chronic form. Additional changes such as a sentinel pile (Mariske) or hypertrophic anal papillae may occur.

Anal fissure or hemorrhoids – how can they be distinguished?

An anal fissure must be clearly distinguished from the following conditions:

• Hemorrhoids, which affect vascular cushions,
• An anal thrombosis, a painful venous thrombosis,
• An anal abscess or anal fistula, which are infectious processes.
• Proctitis, an inflammatory disease of the rectal mucosa.

While bleeding is often the main symptom in hemorrhoids, stabbing pain during bowel movements is the leading symptom in an anal fissure.

What symptoms occur with an anal fissure?

An anal fissure primarily manifests as severe, stabbing pain during bowel movements. The main symptom is a burning or cutting pain in the anal canal that begins during defecation and can last for minutes to hours afterward. The cause is an injury to the highly sensitive mucosa below the dentate line combined with a reflex spasm of the internal sphincter.

The intensity and duration of symptoms vary depending on the stage – acute or chronic – but show a characteristic pattern.

Why does an anal fissure cause severe pain during bowel movements?

While painless bleeding predominates in hemorrhoids, intense pain is the main symptom of an anal fissure. An anal thrombosis usually causes a sudden, persistent swelling with pressure pain. Infectious diseases such as an anal abscess also present with fever and pronounced signs of inflammation. The typical symptom constellation of an anal fissure consists of painful bowel movements, post-defecation burning, and occasional bright red blood traces. The symptoms arise from a tear in the mucosa combined with a reflex sphincter spasm. Early detection is crucial to prevent chronicity and enable targeted therapy.

Acute or chronic anal fissure – what to do in different cases?

An acute anal fissure is a fresh tear of the mucous membrane in the anal canal, usually present for less than six weeks and well treatable with conservative therapy. A chronic anal fissure is diagnosed when the injury lasts longer than six weeks or typical structural changes such as scarring or a sentinel pile (Mariske) occur. The key difference lies in duration, tissue changes, and healing tendency.

In summary, an acute anal fissure often heals through consistent pressure reduction and local measures. The chronic form, however, is characterized by structural remodeling processes and usually requires more intensive or surgical treatment.

Anal fissure – what to do with acute pain? Overview of immediate measures

In the case of an acute anal fissure, quick action is crucial to break the pain-spasm cycle and prevent chronicity. Immediate measures aim to relieve the mucous membrane, reduce sphincter tone, and promote wound healing.

How do I keep stool soft and avoid straining?

The most important measure is consistent stool regulation. Hard or dry stools worsen the tear and delay healing.

Recommended are:

• Adequate fluid intake (about 1.5–2 liters daily, unless contraindicated).
• High-fiber diet

If necessary, osmotically acting stool softeners (e.g., macrogol) can be taken. The goal is a soft, formed stool consistency that can be passed without straining.

How can the sphincter muscle be relaxed?

A reflexive spasm of the internal sphincter is a central obstacle to healing. To reduce tone, the following are suitable:

• Warm sitz baths (10–15 minutes, 1–2 times daily)
• Locally applied, muscle-relaxing ointments (e.g., with nitrates or calcium antagonists, prescribed by a doctor).

Relaxation improves local blood circulation and increases the chance of healing.

Which local treatment protects the mucous membrane?

The injured mucous membrane must be protected from mechanical irritation. For this purpose, nourishing, mucous membrane-protecting ointments or suppositories are suitable (e.g., CANNEFF SUP Suppositories).

• Gentle anal hygiene (no strong rubbing, no aggressive toilet paper).
• Avoid irritating substances.

The goal is to reduce inflammation and irritation in the sensitive anal area.

What helps against pain in anal fissure?

Pain increases sphincter tension and promotes stool retention. Therefore, short-term pain-relieving measures can be useful.

• Locally anesthetic ointments (for a limited time)

If necessary, systemic analgesics can be taken according to medical advice.

Why should strong straining be avoided?

Conscious, strong straining should be avoided. A regular toilet rhythm without time pressure supports physiological defecation.

In an acute anal fissure, regulating bowel movements, relaxing the muscles, and local wound care are the focus. If these measures are implemented early and consistently, most acute fissures heal within a few weeks. It is crucial to break the pain-spasm cycle to prevent chronicity.

Which ointments, suppositories, or medications help with anal fissure?

The drug therapy of an anal fissure primarily aims to reduce pain, relax the sphincter muscle, and promote wound healing. In acute and chronic forms, locally applied ointments or suppositories are used, less commonly systemic medications. Conservative drug measures are a central pillar before invasive therapies such as botulinum toxin injection or surgery.

Medically used options in detail

1. Local pain relief (e.g., lidocaine-containing ointments): These ointments reduce acute pain and burning, which typically occur during or immediately after bowel movements. They are often available over the counter and can be especially helpful in the initial phase.

2. Calcium Channel Blockers (Diltiazem, Nifedipine): Calcium channel blockers are well-evidenced for promoting fissure healing as they reduce the increased resting pressure of the internal sphincter and improve local blood flow. Several studies have shown they have similar or better healing rates than nitroglycerin with fewer side effects (e.g., headaches).

3. Nitrates (e.g., Glycerol Trinitrate Cream): Topical nitrates relax the smooth muscle of the sphincter by releasing nitric oxide, thereby promoting blood flow. However, they can more frequently cause systemic side effects such as headaches.

4. Anti-inflammatory/Nourishing Suppositories: Suppositories with nourishing or mildly anti-inflammatory properties can soothe the mucous membrane and support symptomatic treatment, especially in cases of accompanying irritation.

CANNEFF® SUP for Anal Fissures – How Do CBD and Hyaluronic Acid Support Healing?

CANNEFF® SUP is indicated for anal fissures and represents a conservative therapeutic option in proctology. The rectal suppositories combine cannabidiol (CBD) with hyaluronic acid and specifically target the damaged mucous membrane of the anal canal.

An anal fissure involves a painful tear in the mucous membrane with local inflammation, irritation, and impaired barrier function. This is exactly where the combination of ingredients comes into play: Hyaluronic acid supports moisture retention, promotes the regeneration of the injured tissue, and creates a protective environment, thereby encouraging natural wound healing. CBD has anti-inflammatory and soothing effects on the irritated tissue, which can reduce burning, tightness, and pain. Through this multidimensional effect, CANNEFF® SUP helps stabilize the sensitive anal skin, support mucous membrane healing, and reduce local irritation symptoms. CANNEFF® SUP is suitable for both acute anal fissures and as an adjunct in chronic cases—especially in combination with consistent stool regulation and measures to reduce pressure in the anal canal.

How does proper stool regulation support the healing of an anal fissure?

Consistent stool regulation is a central foundation of therapy for anal fissures because it significantly reduces mechanical stress on the injured mucosa. The goal is to achieve a soft, formed, and lubricated stool consistency that can be passed without strong straining.

Why does hard stool worsen an anal fissure?

Hard, dry stool is the most common cause of an anal fissure. Straining increases pressure in the anal canal, overstretching the sensitive mucosa. Optimized stool consistency causes:

• less stretching of the injured mucosa.
• less friction in the area of the tear.

In addition, the pain-induced sphincter spasm is reduced. This interrupts the so-called pain-spasm cycle, which significantly contributes to chronicity.

How does a soft stool consistency improve blood circulation?

Soft stool reduces the reflexive tension of the internal sphincter muscle. When sphincter tone decreases, local blood flow in the anal canal improves. Adequate perfusion is essential for:

• the oxygen supply to the tissue,
• Cell regeneration
• Wound healing.
• Avoidance of stool retention.

Many affected individuals avoid going to the toilet out of fear of pain. This can lead to stool hardening and further worsen the situation. Regulated and less painful defecation normalizes the evacuation rhythm and prevents renewed mucosal trauma.

Practical measures for long-term stool regulation

• Adequate fluid intake (about 1.5–2 liters daily, if medically justifiable).
• High-fiber diet

If necessary, osmotic laxatives such as macrogol can be taken.

• Regular toilet rhythm without strong straining.

What matters is not the most frequent bowel movements, but a physiologically soft and stress-free passage.

Regulating bowel movements has an immediate positive effect on an anal fissure because it reduces mechanical irritation, indirectly lowers sphincter muscle tone, and improves blood circulation. It thus forms the indispensable basis of any conservative therapy, regardless of whether ointments, suppositories, or other medicinal measures are additionally used.

When should you see a doctor for an anal fissure?

A doctor's visit is advisable if the symptoms are severe, persist for more than one to two weeks, or do not improve despite conservative measures. Especially with intense pain that makes bowel movements difficult or leads to stool retention, a proctological examination is required.

A medical diagnosis is also necessary in cases of:

• recurring bleeding,
• Suspicion of a chronic anal fissure,
• palpable hardenings or sentinel folds (Marisken).
• as well as with additional symptoms such as fever or pronounced swelling.

These signs may indicate complications or other conditions such as hemorrhoids, anal thrombosis, anal abscess, or inflammatory bowel diseases. Early medical treatment increases the chances of healing and prevents chronicity of the anal fissure.

Which conservative therapies help with chronic anal fissure?

In chronic anal fissure (symptoms lasting more than six weeks or structural changes such as hardened edges or a sentinel pile), structured conservative therapy is the priority. The goal is to reduce the increased sphincter tone, improve blood circulation, and promote mucosal regeneration – preferably without surgical measures.

Consistent stool regulation

The basic therapy aims for a consistently soft, lubricated stool consistency. Recommended are:

• High-fiber diet
• Adequate fluid intake
• Osmotic laxatives (e.g., macrogol) as needed.

Stable stool regulation prevents re-injury and supports healing.

How does medicinal sphincter relaxation work?

A central pathophysiological factor of chronic fissures is the increased resting pressure of the internal sphincter muscle. Locally applied agents are used to reduce sphincter tone.

• Calcium channel blockers (e.g., diltiazem, nifedipine).
• Nitrate ointments (e.g., glyceryl trinitrate).

These improve local perfusion and increase the healing rate. The application usually takes place over several weeks.

What role do regeneration-promoting suppositories play?

Rectal suppositories can be used to support mucosal healing. CANNEFF® SUP with CBD and hyaluronic acid are indicated for anal fissures and are part of conservative therapy. Hyaluronic acid supports tissue regeneration and moisture retention, while CBD has anti-inflammatory effects and can reduce local irritation symptoms. This stabilizes the barrier function and promotes healing of the chronically damaged mucosa. CANNEFF® SUP can be used alongside sphincter-relaxing therapy.

Warm sitz baths

Regular warm sitz baths relax the anal muscles, promote blood circulation, and can relieve pain.

When is botulinum toxin considered?

Botulinum toxin can be injected into the internal sphincter muscle as a minimally invasive, non-surgical option. This leads to temporary muscle relaxation and improves healing chances in therapy-resistant, chronic fissure.

When is surgery necessary for anal fissure?

Surgery is necessary for an anal fissure when conservative therapies do not achieve sufficient healing over several weeks or symptoms remain severe and burdensome. This mainly concerns chronic fissures with hardened edges, a sentinel pile (Mariske), or permanently increased sphincter tone.

Indications for surgical therapy are especially:

• Therapy resistance despite consistent medication treatment.
• Persistent severe pain.
• Recurrent fissures.
• Significant impairment of quality of life.

The standard procedure is lateral internal sphincterotomy, in which the internal sphincter muscle is carefully relieved. The goal is to lower resting pressure and thus improve blood flow and wound healing. However, all conservative options should always be exhausted before surgery.

How can recurrent anal fissure be prevented?

The most important measure to prevent a recurrent anal fissure is a permanently regulated, soft stool consistency. Constipation and straining should be consistently avoided.

The key factors are:

• A fiber-rich diet,
• Adequate fluid intake
• Regular, stress-free toilet routine.
• Gentle anal hygiene without mechanical irritation.

For sensitive mucous membranes, additional regenerative local care may be useful to stabilize the barrier function. In the long term, stable bowel function significantly reduces the risk of renewed mucosal injuries in the anal canal.

Sources

Association of the Scientific Medical Societies. (2025). S3 Guideline Anal Fissure (AWMF Registry Number 081-010). https://register.awmf.org/de/leitlinien/detail/081-010

Carapeti, E. A., Kamm, M. A., McDonald, P. J., & Phillips, R. K. S. (1999). Randomised controlled trial shows that glyceryl trinitrate heals chronic anal fissures. Gut, 44(5), 727–730. https://doi.org/10.1136/gut.44.5.727

Knight, J. S., Birks, M., & Farouk, R. (2001). Topical diltiazem ointment in the treatment of chronic anal fissure. British Journal of Surgery, 88(4), 553–556. https://doi.org/10.1046/j.1365-2168.2001.01736.

Nelson, R. L. (2004). Chronic anal fissure. New England Journal of Medicine, 350(2), 193–199. https://doi.org/10.1056/NEJMcp031182

Nelson, R. L. (2011). Operative procedures for fissure in ano. Cochrane Database of Systematic Reviews. https://doi.org/10.1002/14651858.CD002199.pub3

National Institute for Health and Care Excellence. (2013). Chronic anal fissure: 0.2% topical glyceryl trinitrate ointment (ESUOM7). https://www.nice.org.uk/guidance/esuom7

Health Austria GmbH. (2022). Anal fissure. https://www.gesundheit.gv.at/krankheiten/verdauung/analfissur

German Society for Coloproctology. (n.d.). Anal fissure – Professional information. https://koloproktologie.org

Maria, G., Cassetta, E., Gui, D., Brisinda, G., Bentivoglio, A. R., & Albanese, A. (1998). A comparison of botulinum toxin and saline for the treatment of chronic anal fissure. New England Journal of Medicine, 338(4), 217–220. https://doi.org/10.1056/NEJM199801223380402