Anal fissures are one of the most common causes of rectal pain and bleeding, yet many people suffer in silence because they feel uncomfortable discussing these symptoms. Although the pain can be severe and the sight of blood during or after a bowel movement can be alarming, the good news is that most anal fissures can be treated successfully without surgery. 

If you’re experiencing pain during bowel movements, rectal bleeding, or other symptoms of an anal fissure, understanding the causes, treatment options, and prevention strategies can help you find lasting relief and reduce the risk of future episodes.

What Is an Anal Fissure?

An anal fissure is a small tear or crack in the lining of the anus. Although fissures are often small, they can cause significant pain because the area contains many sensitive nerve endings.

A fissure is very similar to a split lip. Think about trying to bite into a sandwich that is too large. If the corner of your mouth splits, the immediate response is to squeeze your lips together and hold pressure on the area. An anal fissure causes a similar reaction. When the skin around the anus tears, the body responds by tightening the anal sphincter muscles.

While this tightening is intended to protect the area, persistent muscle spasm around the anus can significantly increase pain and reduce blood flow needed for healing. The result is a cycle of pain, muscle spasm, and delayed healing.

Anal fissures can be acute or chronic:

Acute Anal Fissures

• Present for less than six weeks
• Approximately 80% heal with conservative treatment
• Often caused by a single episode of trauma, constipation, or diarrhea

Chronic Anal Fissures

• Persist for more than six weeks
• Associated with anal tags (sentinel pile) and hypertrophied anal papilla (internal anal tag)
• Have less than a 60% chance of healing without additional treatment
• May require prescription medications or surgery

What Causes Anal Fissures?

Most anal fissures occur when the anal canal is stretched beyond its normal capacity. The lining of the anus is delicate and can tear when excessive pressure or trauma occurs during bowel movements. Once a tear develops, the body’s natural response is for the anal sphincter muscle to tighten. 

While anyone can develop an anal fissure, certain factors increase the risk. Understanding these causes can help you take steps to prevent future tears and support healthy healing.

Constipation

Passing hard or large stools is one cause of anal fissures. The oversized, firm stool over stretches the anal skin leading to a tear. In addition to causing the initial tear, constipation often leads to straining, which increases pressure within the anal canal and can worsen pain or reopen a healing fissure.

Diarrhea

An acute or chronic onset of diarrhea can cause anal fissures just as often as constipation. Diarrhea caused by infections, gastrointestinal illnesses, food poisoning, or inflammatory bowel conditions often results in repeated bowel movements, increased urgency, and frequent wiping, all of which can contribute to irritation and trauma. In addition, increased intestinal gas and abdominal pressure may place extra strain on the anal tissues and diarrhea can cause additional burning pain.  

Some patients with anal fissures also struggle with digestive symptoms such as bloating, excessive gas, constipation, diarrhea, or sticky stools. These symptoms are often associated with underlying gastrointestinal conditions, including Irritable Bowel Syndrome (IBS). Emerging research suggests that IBS is most likely related to changes in the gut microbiome which leads to bacterial dysbiosis (abnormal balance of the colonic microbiome) or Small Intestinal Bacterial Overgrowth (SIBO) where bacteria implant in the small bowel where they don’t belong – also known as “leaky gut”.

L-glutamine is an amino acid that serves as an important fuel source for the cells lining the small intestine, known as enterocytes. These cells play a critical role in maintaining the integrity of the intestinal barrier. When the intestinal lining becomes irritated or inflamed, some healthcare providers recommend L-glutamine supplementation as part of a broader digestive health plan because it may help support intestinal cell repair and gut barrier function.

One option is a pure L-glutamine supplement that contains no additional ingredients. A common dosage is 2 grams taken twice daily, although patients should always follow the recommendations of their healthcare provider. While individual results vary, some people report improvements in bloating, gas, stool consistency, and overall digestive comfort within several weeks of consistent use.

Childbirth

Some women develop anal fissures during or after vaginal delivery due to increased pressure and stretching of the pelvic and anal tissues.

Anal Trauma

Any injury to the anal can occur from any type of trauma to the canal. The lining of the anus is delicate and once cut or torn with trauma may lead to excessive sphincter spasm and a fissure.  

In some cases, anal fissures may be associated with underlying medical conditions such as:

• Inflammatory bowel disease (IBD)
• Crohn’s disease
• Ulcerative colitis (due to the diarrhea)
• Anal infections
• Certain sexually transmitted infections

Anal Surgery

• Excisional hemorrhoidectomy, condyloma excision (wart excision) and anal tag excision can lead to an anal fissure. I let my patients know the risk of developing a post operative fissure from anal surgery is about 2%. 

Symptoms of an Anal Fissure

The symptoms of an anal fissure can vary from mild discomfort to severe pain. 

Common symptoms include:

• Sharp pain during bowel movements
• Burning or throbbing pain that continues afterward
• Bright red blood on toilet paper or stool
• Visible crack or tear near the anus
• Itching around the anal area

Some patients notice that pain becomes worse 15 to 30 minutes after a bowel movement rather than during defecation. This occurs because the internal anal sphincter naturally relaxes while stool is passing and then tightens again afterward, causing increased pressure on the fissure. 

Because the anal region contains a rich blood supply, bleeding can sometimes appear more significant than expected. Bright red blood may be visible on toilet paper, on the surface of the stool, or occasionally in the toilet bowl. While bleeding from a fissure often stops within a short period of time, persistent rectal bleeding should always be evaluated by a healthcare provider.

What Does an Anal Fissure Feel Like?

One of the most distinctive symptoms of an anal fissure is intense, sharp, glass-like pain during bowel movements. The pain may last for several minutes or even several hours afterward.

Unlike hemorrhoids, which often cause pressure or discomfort, fissures tend to cause sharp, tearing pain. Many patients describe the pain as feeling like passing broken glass.

A healthcare provider can determine the exact cause of symptoms through an examination.

How Are Anal Fissures Diagnosed?

Diagnosis typically begins with a review of your symptoms and medical history. In many cases, a colorectal specialist can diagnose an anal fissure through a visual examination of the outside of the anus alone. Fissures are most often visible to the naked eye with just a look.  

In my practice, once I see the fissure, additional testing such as a digital rectal exam or anoscopy is almost never necessary. In about 2% of cases I do not see the fissure. Even so, based on the symptoms of sharp pain and bleeding, I make the diagnosis and treat the patient conservatively.

For patients who are bleeding and have not had a colonoscopy, once the fissure heals a colonoscopy is strongly recommended to rule out polyps or inflammatory bowel disease if the patient has persistent diarrhea.  

How to Treat an Anal Fissure

The goal of anal fissure treatment is to relieve pain, promote healing, and prevent the fissure from recurring. The best treatment approach depends on whether the fissure is acute or chronic, as well as the severity of symptoms.

The majority of anal fissures, both acute and chronic, heal with conservative treatments that reduce strain on the anal canal and improve blood flow to the affected area.  

Warm Sitz Baths

A sitz bath involves sitting in several inches of warm water for 10-20 minutes, particularly after bowel movements.  Epsom salts can be used as directed.

Warm water helps relax the anal sphincter muscles, reducing pressure on the fissure and improving blood flow to the area.

Benefits of sitz baths include:

• Relaxation of the anal muscles
• Reduced pain and muscle spasms
• Improved circulation
• Temporary symptom relief
• Support for the body’s natural healing process

When the pain of defecation is severe, I recommend defecating in a sitz bath during bowel movements. Sitting in warm water helps to relax the muscles and significantly reduce discomfort during and after defecation.

Avoid Straining During Bowel Movements

Straining places additional pressure on the anal canal and can reopen healing tissue. To reduce strain:

• Add psyllium fiber to bulk the stool making passage easier.
• Respond promptly to the urge to have a bowel movement
• Avoid sitting on the toilet for extended periods
• Do not force bowel movements
• Maintain a high-fiber diet and adequate hydration

These habits can help prevent further injury and improve healing outcomes.

Use Stool Softeners When Needed

Over-the-counter stool softeners may be helpful for people experiencing constipation or hard stools. Unlike stimulant laxatives, stool softeners work by increasing the amount of water in the stool, making it easier to pass. This can reduce pain during bowel movements and help protect the fissure while it heals.

Your healthcare provider can recommend the most appropriate option based on your symptoms and medical history.

Prescription Medications

If conservative treatments do not provide relief or the fissure becomes chronic, your healthcare provider may prescribe medications designed to relax the anal sphincter and improve blood flow.

These medications generally require consistent use and may take approximately two weeks before patients notice significant improvement.

It is important to note that nitroglycerin, diltiazem, nifedipine, and Rectiv may affect blood pressure. Patients should discuss all medications they are taking with their healthcare provider, particularly medications used for erectile dysfunction, before beginning treatment.

Common prescription treatments include:

Topical Nitroglycerin

Nitroglycerin ointment helps increase blood flow to the fissure, which can promote healing. It also reduces pressure in the anal sphincter muscle.

Some patients experience headaches as a side effect, but the medication can be highly effective when used as directed.

Calcium Channel Blockers

Topical medications such as diltiazem or nifedipine may be prescribed to relax the anal sphincter muscle and improve circulation.

These treatments are often well tolerated and may be used as an alternative to nitroglycerin.

Pain Relief

Managing pain is an important part of treatment. In addition to sitz baths, your healthcare provider may recommend:

• Over-the-counter pain relievers
• Topical anesthetic creams
• Gentle cleansing after bowel movements

Keeping the area clean and minimizing irritation can help make the healing process more comfortable.

Dietary Measures 

Fiber Intake

One of the most effective ways to treat and prevent anal fissures is to increase your fiber intake. Fiber absorbs water in the colon, helping to create larger, softer stools that are easier to pass and require less straining during bowel movements.

While it may seem counterintuitive, larger, well-formed stools are often better for fissure healing than small, thin, or loose stools. Soft, bulky stools gently stretch the anal canal, which can help relax the sphincter muscles and improve blood flow to the area. This process is similar to physical therapy after an injury, where controlled stretching helps tissues heal with greater flexibility and reduces the risk of reinjury.

In contrast, small or narrow bowel movements may allow the fissure to heal in a more contracted state, making it easier for the tissue to tear again in the same location. Consistently passing soft, bulky stools during the healing process can help promote proper healing and reduce the likelihood of recurrence.

Fiber may also help decrease straining and reduce pressure within the anal canal. Less straining means less muscle spasm and less swelling of nearby hemorrhoidal tissue, both of which can improve circulation and support healing.

Sources of fiber include:

• Supplemental fiber
  • (RAW psyllium fiber supplement) PERFECT P.O.O.P.® 
• Foods rich in fiber
  • Fruits
  • Vegetables
  • Whole grains
  • Beans and legumes
  • Nuts and seeds

In addition to increasing fiber-rich foods in your diet, many patients benefit from a fiber supplement. Psyllium husk is one of the most effective options because it absorbs water and helps create larger, softer, well-formed stools that are easier to pass. This can reduce straining during bowel movements and support the healing of an anal fissure.

One psyllium supplement I frequently recommend is PERFECT P.O.O.P.®, a raw psyllium fiber product formulated to mix smoothly and be easier to take than many traditional fiber supplements. It contains no added sugar, artificial sweeteners, flavorings, colorants, preservatives, or unnecessary additives. When mixed with approximately 4–5 ounces of juice or a milk alternative, it can be a simple and convenient way to increase daily fiber intake.

One teaspoon of psyllium provides approximately 5 grams of fiber, making it an easy way to help reach the recommended daily intake of 30–35 grams. Unfortunately, the average American consumes only 10–15 grams of fiber per day, leaving many people well below the recommended amount.

When taking psyllium or any fiber supplement, it is essential to drink plenty of water throughout the day (32 to 64 ounces). Fiber works by absorbing fluid in the digestive tract, and inadequate hydration can actually worsen constipation. A good goal is to increase both fiber and water intake gradually to allow your body time to adjust.

Beyond supporting regular bowel movements, psyllium fiber has been associated with several additional health benefits, including improved colorectal and anorectal health, cholesterol management, blood sugar regulation, weight control, and overall digestive wellness. Pairing adequate fiber intake with a diet lower in saturated fat and cholesterol can further support long-term gastrointestinal and cardiovascular health.

Stay Hydrated

Fiber works best when paired with adequate hydration. Drinking plenty of water helps keep stool soft and easier to pass, reducing pressure on the anal canal during bowel movements.

Although individual hydration needs vary, many adults benefit from drinking at least eight glasses of 4 ounces of water per day. People who exercise frequently or live in hot climates may require even more fluids. Limiting dehydrating beverages such as excessive alcohol can also support healthy bowel function.

Probiotics and Prebiotics

A healthy gut microbiome plays an important role in digestive health, immune function, and regular bowel movements. Many healthcare providers believe that modern diets, stress, medications, and lifestyle factors can contribute to an imbalance in gut bacteria, often referred to as dysbiosis. When this occurs, digestive symptoms such as bloating, gas, constipation, diarrhea, and irregular bowel habits may become more common.

Probiotics are beneficial bacteria that help maintain a healthy balance within the digestive tract. Research has shown that certain probiotic strains can support immune function and promote overall gastrointestinal health. Probiotics can be obtained through fermented foods such as yogurt, kefir, sauerkraut, and kimchi, or through high-quality dietary supplements.

Equally important are prebiotics, which serve as food for beneficial bacteria. Ingredients such as inulin and fructooligosaccharides (FOS) help nourish healthy gut microbes, allowing them to thrive. As these beneficial bacteria ferment prebiotic fibers, they produce short-chain fatty acids that support the health of the intestinal lining and help maintain a balanced digestive environment. These compounds may also help create conditions that discourage the overgrowth of less desirable bacteria, supporting overall colorectal and anorectal health.

One probiotic supplement I often recommend is Super POOPer Probiotics®, which contains four clinically researched strains of beneficial bacteria: Lactobacillus acidophilus, Lactobacillus plantarum, Bifidobacterium longum, and the extensively studied HN019® strain of Bifidobacterium lactis. These probiotic strains have demonstrated safety and digestive health benefits and have been selected for their ability to survive the digestive process and adhere to the intestinal lining, helping support a healthy gut microbiome. By promoting a balanced bacterial environment, probiotics may improve digestive function, support regular bowel movements, and contribute to overall colorectal and anorectal health.

Micronized Diosmin

Many patients with chronic anal fissures also experience enlarged hemorrhoids. This often occurs because the muscle spasm associated with a fissure increases pressure within the anal canal, causing hemorrhoidal veins to become engorged. As hemorrhoids enlarge, they can further increase anal pressure and reduce blood flow to the fissure, creating an environment that may slow healing.

Micronized diosmin is a naturally occurring bioflavonoid derived from citrus peels, particularly immature oranges. It has been widely studied for its effects on venous circulation and hemorrhoid symptoms. Research suggests that diosmin may help support healthy blood vessel function, reduce inflammation, improve venous tone, and decrease swelling associated with hemorrhoids while indirectly supporting fissure healing.

One option formulated specifically for anorectal health is R.H.O.I.D.- AID®, a micronized diosmin and hesperidin supplement developed using the same active ingredient ratio found in the clinical studies evaluating Daflon®, a well-known micronized flavonoid formulation. The product contains 90% diosmin and 10% hesperidin and is micronized to enhance absorption.

As with any supplement, patients who are pregnant, breastfeeding, taking blood thinners, or managing chronic medical conditions should consult their healthcare provider before use.

When Conservative Treatments Don’t Work

Most acute anal fissures heal within several weeks when treated appropriately. However, if symptoms persist despite lifestyle changes and medication, additional treatments or surgery may be recommended.

Botox Injections

Botulinum toxin (Botox) injections may be used to temporarily relax the internal anal sphincter muscle. By reducing muscle spasm, Botox can improve blood flow and promote healing. While some patients experience good results, recurrence remains possible once the effects wear off.

Silver Nitrate Therapy

In select cases, silver nitrate may be used to cauterize chronic fissure tissue. This treatment promotes the formation of new tissue and may help restart the healing process. Because it does not address the underlying muscle spasm, it is typically reserved for fissures that have not responded to other conservative therapies.

The sooner treatment begins, the more likely it is that the fissure will heal without requiring a procedure. If you continue to experience pain, bleeding, or recurring symptoms, it’s important to consult a healthcare provider for further evaluation.

When Is Surgery Needed?

Most anal fissures heal without surgery, especially when treated early with dietary changes, hydration, sitz baths, and medication. However, if a fissure becomes chronic or continues to cause significant pain and bleeding despite conservative treatment, a surgical procedure may be recommended. 

Common surgical procedures include:

Lateral Internal Sphincterotomy

This procedure involves making a small incision in a portion of the internal anal sphincter muscle. By permanently reducing muscle tension, blood flow improves and healing can occur. Studies report cure rates at 98%.

Advancement Flap Procedures

In certain patients, such as those with Crohn’s disease, chronic diarrhea, anal scarring, or existing continence concerns, surgeons may use healthy nearby tissue to cover the fissure rather than cutting the sphincter muscle.

Chronic fissures often develop scar tissue and persistent muscle spasms that reduce blood flow to the area, making natural healing more difficult. In these cases, surgery can help relax the anal sphincter muscle, improve circulation, and create an environment that allows the fissure to heal. Your healthcare provider will typically consider surgical options only after nonsurgical treatments have failed to provide lasting relief.

Can Anal Fissures Heal on Their Own?

Yes, many acute anal fissures can heal on their own, particularly when the underlying cause, such as constipation, hard stools, or straining during bowel movements, is addressed. Improving hydration, increasing fiber intake, and adopting healthier bowel habits often allows the tear to heal naturally within a few weeks. However, healing can be delayed if the fissure is repeatedly irritated by ongoing constipation or frequent diarrhea. 

If symptoms such as pain, bleeding, or discomfort persist beyond several weeks, or if fissures continue to return, it’s important to seek medical evaluation. Chronic anal fissures are less likely to heal without treatment because ongoing muscle spasms in the anal sphincter can restrict blood flow to the area, preventing proper healing. Left untreated, chronic fissures may become more painful, develop scar tissue, and require prescription medications or surgical intervention to resolve.

When Should You See a Doctor?

You should seek medical attention if you experience:

• Persistent rectal bleeding
• Severe pain during bowel movements
• Symptoms lasting more than a few weeks
• Recurrent fissures
• Signs of infection

While anal fissures are common, similar symptoms can occur with other gastrointestinal conditions that require medical evaluation.

Frequently Asked Questions

Are anal fissures serious?

Most anal fissures are not serious but are seriously painful and annoying.  Many will heal with conservative treatment. However, persistent symptoms should be evaluated by a healthcare provider.

How long does it take an anal fissure to heal?

Healing time depends on the severity of the fissure and whether it is acute or chronic.

Typical healing timelines include:

• Acute fissures: Two weeks to feel 50% better with addition of psyllium fiber PERFECT P.O.O.P.®  and a sphincter relaxing ointment then 1-3 months to completely heal.
• Chronic fissures: May take longer and require medical treatment

Following treatment recommendations can significantly improve healing outcomes.

Can stress cause anal fissures?

Stress does not directly cause fissures, but it may contribute to digestive issues such as constipation or diarrhea that increase risk.

Is bleeding from an anal fissure normal?

Bright red blood on toilet paper or in the toilet bowl is a common symptom of an anal fissure.

Can anal fissures come back?

Yes, people who experience chronic constipation or other risk factors may develop recurrent fissures.

What is the fastest way to heal an anal fissure?

The most effective approach typically includes increasing fiber intake, staying hydrated, avoiding straining, and following treatment recommendations from a healthcare provider.

Should I get a colonoscopy if I have an anal fissure?

Not everyone with an anal fissure requires a colonoscopy. However, any rectal bleeding, a family history of colorectal cancer, abnormal bowel habits, or other concerning symptoms may warrant further evaluation.

Since the number one cause of cancer related death in younger Americans is due to colorectal cancer, many specialists recommend a colonoscopy when rectal bleeding is present as bleeding is a symptom requiring a colonoscopy, even if an anal fissure is diagnosed.

Find Relief from Anal Fissure Symptoms

Anal fissures can be painful and disruptive, but most cases respond well to treatment. By improving bowel habits, staying hydrated, and seeking medical care when needed, many people can find relief and prevent future fissures.

If you are experiencing persistent rectal pain, bleeding, or other concerning symptoms, a consultation with a colorectal specialist can help determine the cause and create a personalized treatment plan. Contact us to set up an appointment today to find relief.