Anal Fissures: The Most Common Cause of Anal Pain — What Causes the Tear, Why It Hurts So Much, and How It Heals

Q: Can an anal fissure heal on its own?

Yes, most do. Acute fissures typically heal within a few days to weeks with simple self-care — water, fiber, sitz baths, and gentle hygiene. But fissures that last more than eight weeks are chronic and usually need prescription treatment or a minor procedure to heal.

Q: How do I know if it's a fissure or hemorrhoids?

Fissures cause sharp, episodic pain during and after bowel movements, and 90% of them hurt. Hemorrhoids are more common but don't always hurt, and their discomfort can be constant. Because they can look and feel alike, only an exam can confirm which one you have.

Q: Is an anal fissure the same as anal cancer?

No. A fissure is a simple tear in the skin lining the anal canal. However, atypical fissures — off the midline, multiple, or non-healing — can sometimes signal underlying conditions including malignancy, which is why persistent or unusual fissures should be evaluated by a provider.

Q: How long does an anal fissure take to heal?

Most heal in a few days to a few weeks. Fissures treated within two weeks of symptoms heal at rates approaching 100%; chronic fissures (more than 8 weeks) typically need six to twelve more weeks of treatment to close.

Q: Why do some fissures keep coming back?

Chronic fissures follow a cycle: pain makes the sphincter muscles spasm, the spasm reduces blood flow and pulls the tear apart, poor blood flow prevents healing, and the unhealed tear keeps hurting. Roughly 35% heal without treatment at least temporarily, but recurrence is common without addressing the muscle tension.

Q: Can constipation cause an anal fissure?

Yes — it is the leading cause. Hard stools and straining tear the delicate lining of the anal canal, especially in the back midline where blood supply is weakest. Chronic constipation is found in about 14% of fissure patients versus 4% of matched controls.

Q: When is surgery the right option for a fissure?

Surgery (lateral internal sphincterotomy) is considered when a fissure won't heal with medication or keeps recurring after healing. It is a minor same-day procedure with roughly a 90% success rate and healing in about 96% of long-term study patients.

Q: Does an anal fissure ever mean something more serious?

Usually not — fissures are common and not dangerous. But fissures in unusual locations, multiple fissures, or fissures that won't heal can be associated with inflammatory bowel disease, infections, or other systemic conditions, so non-healing fissures warrant proper evaluation.

Dr. Baraa Alnahhal

4 days ago

11 min read

Updated: 2 days ago

Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026

Editorial note: This article is for general education only. It is not medical advice, a diagnosis, or a treatment plan. Anal pain and rectal bleeding have many possible causes, and a healthcare provider is the right person to confirm a fissure and rule out more serious conditions.

TL;DR

An anal fissure is a crack or tear in the delicate lining of the anal canal — most often caused by passing hard stools or straining. It is one of the most common causes of anal pain: 90% of fissures hurt, versus many painless hemorrhoids. Most U.S. estimates put new cases at 240,000–342,000 per year, with a lifetime risk of roughly 8% and an annual incidence of about 1 in 1,000 people. Most fissures heal on their own within days to a few weeks with simple self-care (fiber, water, sitz baths), but about 40% of acute fissures become chronic (lasting more than 8 weeks), at which point prescription ointments or a minor surgery (with roughly a 90–96% success rate) usually ends the problem.

Quick Answer: What Is an Anal Fissure?

An anal fissure is a crack or tear in the soft lining of the anal canal, most often caused by anal trauma — especially straining to pass hard stools or chronic diarrhea. It causes sharp, tearing pain during and after bowel movements, bright red blood, and often anal muscle spasms. Most heal on their own within days to weeks with self-care, but fissures that last more than eight weeks are chronic and may need prescription medication or minor surgery, which succeeds in about 9 in 10 patients.

What Is an Anal Fissure?

An anal fissure is a crack or tear in the lining of the anal canal. The tear sits at the end of the digestive tract, and it is one of the most common causes of anal pain and rectal bleeding — especially pain during bowel movements. Anal trauma usually causes a fissure, with straining to pass hard stools being the most frequent trigger. Some fissures happen suddenly; others develop gradually. Some heal quickly; others resist healing for months.

A fissure is formally defined as a longitudinal tear in the anoderm, the thin, delicate skin-like lining just inside the anal opening. Most fissures are solitary and sit along the back midline of the anus, where blood supply is weakest — the blood flow there is less than half that of other areas of the anal canal. That poor blood flow is one reason some fissures struggle to heal.

How Common Are Anal Fissures?

Anal fissures are very common, especially in infants and pregnant women. Approximately half of all people who get anal fissures get their first one before turning 40. Incidence is similar between sexes overall, though population studies show clear age patterns: rates peak in adults aged 25–34 and in males aged 55–64, and are higher in young women aged 12–24.

Measure	Estimate
Annual incidence (U.S. population study)	0.11% — about 1.1 per 1,000 person-years
Peak incidence by age	0.18% per year in ages 25–34
New U.S. cases per year	240,000–342,000
Lifetime risk	~7.8% (roughly 1 in 13 people)
Fraction of cases in women	58%
Women with fissure after delivery	15% (vs. 2% before delivery in one study)
First fissure before age 40	About half of all cases

The pregnancy connection matters: in one prospective study of 165 women tracked through the final months of pregnancy and the first 10 weeks postpartum, only 2 had a fissure before delivery, but 15% developed one after delivery — and half of those appeared more than two weeks after the birth. Infants are also affected, which is why pediatric providers see fissures regularly.

What Does an Anal Fissure Feel Like?

The hallmark symptom is sharp pain when pooping — people describe it as sharp, tearing, cutting, or burning. The pain is most intense during a bowel movement but can last for minutes to several hours afterward, and it may radiate to the buttocks, upper thighs, or lower back. Alongside the pain, most people notice fresh, red blood — often streaks rather than heavy bleeding. Burning or itching during bowel movements is common, and some people develop anal muscle spasms or a small lump of skin near the tear.

Symptom	What it looks like
Sharp anal pain	Tearing, cutting, or burning pain during bowel movements
Prolonged pain afterward	Pain lasting minutes to hours after pooping
Bright red blood	Fresh blood in the stool or on the toilet paper
Burning or itching	Especially during bowel movements
Muscle spasms	Anal sphincter clenching and spasm
Small lump	Skin bump near the tear (sentinel tag)

Anal Fissure vs. Hemorrhoid: How Do You Tell Them Apart?

Fissures and hemorrhoids share similar symptoms and causes, and they are easy to mistake for one another. Both can result from straining, and both can cause rectal bleeding, anal pain, and anal itching. The distinction matters because treatment differs.

Feature	Anal fissure	Hemorrhoid
Pain	90% of fissures cause pain	Don't always cause pain
Pain pattern	Occurs in episodes, tied to bowel movements	Can be constant
Bleeding	Streaks of bright red blood	Often drips or pools
Main symptom	Pain is the defining feature	Bleeding and a bulge are typical
Frequency	Less common overall	More common overall

In practice, pain during and after bowel movements points toward a fissure, while a painless bulge or constant ache points toward a hemorrhoid. Only an examination can confirm which one — or whether something else is going on entirely.

What Causes Anal Fissures?

The anatomy explains a lot. Toward the end of the anus, the skin is like the outside skin of the body. But the upper portion — where fissures usually happen — is lined with the same soft mucosa that lines the rest of the large intestine. This tissue is thinner and more delicate, so it tears more easily, which is why fissures occur in babies too. The anus is surrounded by two circular muscles called the anal sphincters. If these muscles are too tight, they add tension that makes tearing easier and reduce blood flow to the already fragile tissue.

Common cause	How it triggers a fissure
Chronic constipation	Hard stools scrape and stretch the delicate lining
Straining	Force tears the thin anoderm
Chronic diarrhea	Repeated irritation wears the tissue down
Childbirth	Anal trauma during delivery
Obstructed defecation syndrome	Difficulty evacuating strains the area
Infant dyschezia	Infant straining and discomfort
Penetration	Direct trauma to the anal canal
Diaper rash	Irritated skin tears more easily

Underlying conditions can also contribute to fissures or keep them from healing, including inflammatory bowel disease (IBD), sexually transmitted infections (STIs), prior surgery, anal cancer, and tuberculosis. Fissures that appear off the midline or in multiple locations are atypical and deserve extra medical evaluation for these systemic causes.

What Increases Your Risk of Anal Fissures?

A large U.S. population study matched each fissure case with three similar patients who did not have a fissure, and found several comorbidities that were significantly more common in the fissure group. These associations don't prove cause, but they flag the conditions most worth managing.

Risk factor / comorbidity	Prevalence in fissure group vs. matched controls
Chronic constipation	14.2% vs. 3.6%
Hypothyroidism	14.7% vs. 10.4%
Obesity	13.0% vs. 7.7%
Young adult age (25–34)	Highest annual incidence: 0.18%
Recent childbirth	15% developed fissures after delivery in one study
Low dietary fiber intake	A noted risk factor for acute fissures

What Happens When an Anal Fissure Won't Heal?

When an acute fissure lingers, a vicious cycle takes over. The fissure is painful, and the pain makes the anal muscles clench and spasm. The tight, spastic muscles do two damaging things at once: they pull the edges of the tear apart, and they reduce blood flow to the tissue that needs blood to repair itself. So the fissure stays open, stays painful, and gets harder to heal — which makes the pain worse, which makes the muscles clench harder.

Clinicians draw the line between acute and chronic at eight weeks: a fissure that lasts more than eight weeks is chronic. Chronic fissures typically follow a cyclical pattern of intermittent healing and recurrence, and about 35% will heal at least temporarily even without treatment — but the majority persist or recur without active care.

If a chronic fissure remains untreated, it can lead to real complications:

Complication	What it is
Fecal impaction	Hard stool gets stuck because pain makes people avoid bowel movements
Anal stenosis	Long-term damage narrows the anal canal
Anal fistula	A chronic tunnel forms from the anal canal to the skin

How Are Anal Fissures Diagnosed?

Diagnosis is usually quick and visual. A healthcare provider will ask about your symptoms, then try to see the fissure directly — you may lie on your stomach or side while they separate the buttocks to look. If the area is simply too painful to examine, providers can often safely assume a fissure is present based on the symptom pattern.

A digital rectal exam — a lubricated, gloved finger — can help open the anus slightly, notice tenderness or muscle spasms, and rule out other causes. If a fissure is off the midline, appears multiple times, or won't heal, further evaluation may look for underlying conditions such as IBD, infection, or malignancy.

How Long Do Anal Fissures Take to Heal?

Most anal fissures heal within a few days to weeks. The sooner treatment starts, the better the odds: fissures treated within two weeks of symptoms have healing rates approaching 100%, acute fissures overall heal about 80% of the time, and chronic fissures heal only about 40% of the time without stronger treatment. Chronic anal fissures — those lasting more than eight weeks — may take an additional six to twelve weeks of treatment to finally close.

Fissure stage	Typical healing rate
Symptoms < 2 weeks	~100%
Acute (under 8 weeks)	~80%
Chronic (over 8 weeks)	~40% without escalated treatment
Chronic, no intervention at all	~35% eventually heal temporarily
Chronic, conservative care (ASCRS)	At least 50%
Chronic, topical therapy	65–95%

How Are Anal Fissures Treated?

Treatment follows an escalating ladder. Most fissures heal with simple self-care; chronic fissures need medical help to relax the sphincter muscles and restore blood flow so the tear can close.

Treatment step	How it works
Self-care	Fiber, water, sitz baths, gentle wiping
Lidocaine or pain-relief cream	Topical relief while acute fissures heal on their own
Nitroglycerin ointment	Vasodilator that restores blood flow and relaxes the sphincter; headaches are a common side effect
Calcium channel blockers (diltiazem, nifedipine)	Alternative muscle and blood-vessel relaxants if nitroglycerin fails
Botox injection	Temporarily relaxes the sphincter for ~3 months, giving the fissure time to heal
Bulk laxatives (psyllium)	Draw fluid into the gut to soften stools
Lateral internal sphincterotomy	Minor surgery with a ~90% success rate

Surgery: When Medications Aren't Enough

If a fissure won't heal with medication, or heals and then returns, a minor procedure can end the cycle. The operation is called an internal sphincterotomy: while you are asleep under sedation, a surgeon makes a small cut into the anal sphincter muscle to release the tension permanently. You go home the same day. Surgery has about a 90% success rate — and independent research reports are even more encouraging, with a long-term study finding fissures healed in 96% of patients by a median of three weeks, and recurrence in only 8%. A recent meta-analysis of randomized trials found overall postoperative healing of 90.2% with a recurrence rate of 3.7%.

How Do You Care for an Anal Fissure at Home?

Most fissures will heal on their own, and self-care speeds the process. Providers recommend a consistent routine while symptoms last:

Self-care measure	Why it helps
Stool softener	Makes bowel movements more comfortable
Step stool while on the toilet	Supports feet in a squatting position
Gentle wiping	Soft paper or alcohol-free wet wipes; consider a bidet or showering after bowel movements
Topical ointment or petroleum jelly	Seals in moisture and promotes healing
Sitz baths, 2–3 times daily	10–15 minutes of warm water soak relieves pain and relaxes muscles
More water and fresh produce	More fruits, vegetables, and fluids keep stools soft
Avoid spicy foods and nuts	Reduce irritation while symptoms last

Can Anal Fissures Be Prevented?

The best prevention targets the causes. Treat chronic conditions that affect the anus early — bowel trouble, unexplained pain, or underlying disease — because treating them sooner prevents complications like fissures from developing or returning. The everyday strategy is staying regular: drink plenty of water, eat enough fiber, and prevent constipation before it becomes a medical problem.

Key Takeaways

Anal fissures are common, painful, and usually temporary. They are cracks in the delicate lining of the anal canal, most often triggered by hard stools and straining — and roughly 240,000–342,000 new cases appear in the U.S. each year, with a lifetime risk near 8%. Ninety percent of fissures hurt, which is what separates them from often-painless hemorrhoids. Most heal within days to weeks with water, fiber, sitz baths, and gentle care — but about 40% of acute fissures become chronic (lasting more than eight weeks), when the pain-spasm-poor-blood-flow cycle locks the tear open. Chronic fissures respond to prescription ointments, Botox, or a minor same-day surgery that succeeds in roughly 9 in 10 patients. See a healthcare provider if pain and bleeding persist beyond a few weeks, recur repeatedly, or come with weight loss, fever, or off-midline tears — those patterns deserve evaluation rather than more self-care.

If you're dealing with anal pain that comes and goes for weeks, don't tough it out — chronic fissures rarely resolve on their own, and modern treatments work. Talk to a healthcare provider or colorectal specialist about the right next step for you.

Frequently Asked Questions

Can an anal fissure heal on its own?