Anal Fissure: Symptoms, Causes, and Treatment (2026)
An anal fissure is a tear in the skin at the anal opening. The classic sign is sharp, tearing pain during a bowel movement that can last for hours afterward, often with a small amount of bright red blood. Most acute fissures settle within a week or two using warm sitz baths, more fiber and water, an
An anal fissure is a small tear in the lining of the anus, and it is one of the most common causes of sharp anal pain during and after bowel movements. Like hemorrhoids, fissures are a routine anorectal problem, and most heal with simple care. This guide covers the symptoms, causes, treatment options, and the warning signs that mean it is time to see a doctor.
Quick Answer
An anal fissure is a tear in the skin at the anal opening. The classic sign is sharp, tearing pain during a bowel movement that can last for hours afterward, often with a small amount of bright red blood. Most acute fissures settle within a week or two using warm sitz baths, more fiber and water, and avoiding straining. Fissures that persist or keep returning need medical care.
See a doctor if bleeding is heavy, if pain or bleeding lasts more than a week or two, if a fissure keeps coming back, or if the tear is off to the side of the anus rather than front or back. An off-midline fissure can be a sign of Crohn disease or another condition, and rectal bleeding should always be evaluated rather than assumed to be minor.
What Are Anal Fissures?
An anal fissure is a tear or laceration in the soft lining of the anus. It starts as a small tear in the skin at the anal opening. The American Society of Colon and Rectal Surgeons (ASCRS) explains that almost all fissures occur on the midline of the anus, in the back or the front. Fissures located on the sides can be a sign of other conditions and deserve a closer look.
Fissures are grouped by how long they last. Acute fissures are freshly developed and cause less lasting discomfort. If they do not heal, they can become chronic fissures, which are more painful and can lead to complications, so they need medical attention.
Symptoms of Anal Fissures
Anal fissures can be painful right from the start, which makes them relatively easy to recognize. The most common symptoms include:
- Sharp pain during a bowel movement that can last for minutes to several hours afterward
- Spasms of the anal sphincter, the muscle that controls passing stool
- Bright red blood on the stool or toilet paper
- Itching or a burning sensation around the anus
- A visible crack or tear in the skin at the anal opening
- A small lump of skin, called a skin tag or sentinel pile, next to a chronic tear
Unlike some other anorectal conditions, people with fissures often feel fine between bowel movements, because the pain is triggered by passing stool. A chronic fissure can sometimes produce a foul-smelling discharge or extra tissue growth near the tear.
Causes of Anal Fissures
The primary cause is trauma to the lining of the anus. According to Mayo Clinic, common triggers include:
- Passing hard or large stools and straining during bowel movements
- Chronic constipation or, less obviously, chronic diarrhea
- Childbirth
- Anal intercourse
- A tight or spasming anal sphincter with reduced blood flow to the area, which slows healing
Less commonly, fissures are associated with Crohn disease, other inflammatory bowel disease, and certain infections. This is one reason a fissure that sits off the midline, or one that will not heal, should be evaluated by a clinician.
How Anal Fissures Are Diagnosed
A doctor can usually diagnose a fissure with a gentle physical exam, since the tear is often visible on inspection. The location offers a clue about the cause: a tear on the side of the anal opening, rather than front or back, can point to Crohn disease or another condition, and may prompt additional tests. Self-diagnosis is not reliable, because infections, abscesses, hemorrhoids, and inflamed skin tags can cause similar symptoms.
Treatment for Anal Fissures
Most acute fissures heal with conservative care. Treatment usually starts at home and escalates only if simple measures fail.
Home Care
- Warm sitz baths. Soaking the area in warm water for 10 to 20 minutes several times a day, especially after bowel movements, relaxes the sphincter spasm that drives much of the pain. See our sitz bath guide.
- More fiber and fluids. Softer, bulkier stools reduce the trauma that reopens a fissure. Aim for a high-fiber diet and plenty of water.
- Do not strain or delay. Straining and holding it in both work against healing.
- Gentle hygiene. Keep the area clean and dry, and wipe with a soft, unscented material.
Medical Therapy
If home care is not enough, a doctor may prescribe a topical treatment to relax the sphincter and improve blood flow so the tear can heal, such as a nitroglycerin ointment or a calcium channel blocker cream (for example, diltiazem). A numbing agent like lidocaine can ease pain but does not heal the fissure, and it should be used only with medical guidance.
Non-Surgical and Surgical Options
For stubborn chronic fissures, options include a Botox injection to temporarily relax the sphincter muscle, or surgery. Mayo Clinic notes that a procedure called lateral internal sphincterotomy, which releases a small part of the sphincter muscle, is highly effective for chronic fissures, though it carries a small risk of affecting continence. A colorectal specialist can walk you through the trade-offs.
Prevention
Because most fissures come from hard stools and straining, prevention centers on keeping bowel movements soft and regular:
- Eat enough fiber and drink enough water
- Treat constipation and diarrhea promptly rather than letting either persist
- Do not ignore the urge to have a bowel movement
- Keep the anal area clean and dry, and avoid rough or scented toilet paper
- For infants, change diapers frequently and treat constipation early
When to See a Doctor
Most acute fissures improve within a week or two of home care. See a doctor if pain or bleeding lasts longer than that, if a fissure keeps returning, if bleeding is heavy, or if the tear sits off the midline. Do not assume rectal bleeding is only a fissure or hemorrhoid, since bleeding can occasionally signal a more serious condition and should be evaluated. Not sure whether it is a fissure or a hemorrhoid? See our anal fissure vs hemorrhoids guide.
Frequently Asked Questions
What are the symptoms of an anal fissure?
Sharp pain during a bowel movement that can linger afterward, bright red blood on the stool or toilet paper, itching or burning around the anus, a visible crack in the skin, and sometimes a small skin tag near the tear.
What causes anal fissures?
Most fissures come from trauma to the anal lining, usually passing hard, dry stools or straining. Chronic diarrhea, childbirth, anal intercourse, and a tight sphincter with reduced blood flow also contribute.
How do you treat an anal fissure at home?
Warm sitz baths several times a day, more fiber and water to soften stools, avoiding straining, and gentle hygiene. Most acute fissures heal within a week or two with this approach.
When should I see a doctor for an anal fissure?
If pain or bleeding lasts more than a week or two, if a fissure keeps returning, if bleeding is heavy, or if the tear is off to the side of the anus rather than the midline.
What is the difference between an anal fissure and a hemorrhoid?
A fissure is a tear that causes sharp, tearing pain during bowel movements. A hemorrhoid is a swollen vein that more often causes pressure, itching, a soft lump, or painless bleeding. Both can bleed, so a doctor visit helps confirm which one you have.
References and Clinical Sources
- Anal Fissure: Symptoms and Causes. Mayo Clinic.
- Anal Fissure: Diagnosis and Treatment. Mayo Clinic.
- Anal Fissure. American Society of Colon and Rectal Surgeons (ASCRS).
This article is for informational purposes and does not replace professional medical advice.
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