Anal Fissure

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Anal Fissure

Topic Overview

What is an anal fissure?

An anal fissure is a tear in the lining of the lower rectum (anus) that causes pain during bowel movements. It is a common condition. Anal fissures do not lead to more serious conditions.

Most anal fissures heal with home treatment after a few days or weeks (acute anal fissures). If you have an anal fissure that has not healed after 6 weeks, it is considered a long-term problem (chronic). You may need medicine to help a chronic anal fissure heal. Surgery may be necessary for fissures that do not heal with medicine.

Anal fissures affect people of all ages, particularly young and otherwise healthy people. They are equally common in men and women.

Sometimes an anal fissure and a hemorrhoid develop at the same time.

What causes an anal fissure?

Anal fissures are caused by injury (trauma) to the anal canal. Injury can happen if:

  • You pass a large stool that stretches the anal canal.
  • You are constipated and try to pass a hard stool.
  • You have repeated diarrhea.

Childbirth can also cause trauma to the anal canal. During childbirth, some women develop anal fissures. Fissures can also be caused by digital insertion (as during an examination), foreign body insertion, or anal intercourse.

Because many people get constipated or have diarrhea without getting anal fissures, many experts believe there is some other cause of anal fissures. Some people may have excessive tension in the two muscular rings (sphincters) controlling the anus. The external anal sphincter is under your conscious control. But the internal anal sphincter is not under your control. This muscle remains under pressure, or tension, all of the time. A fissure may develop if the internal sphincter's resting pressure becomes too high, causing spasm and reducing blood flow to the anus. This high resting pressure can also keep a fissure from healing.

In some cases, an anal fissure may be caused by Crohn's disease, an inflammatory bowel disease (IBD) that causes bloody diarrhea, abdominal (belly) pain, fever, weight loss, and fissures or fistulas near the anus.

What are the symptoms?

An anal fissure causes a sharp, stinging, or burning pain during a bowel movement. The pain, which can be severe, may last for a few hours.

Fissures may itch. They often bleed lightly or cause a yellowish discharge. You may see a small spot of bright red blood on toilet tissue or a few drops in the toilet bowl. The blood is separate from the stool. Very dark, tarry stools or dark red blood mixed with stool indicates some other condition, possibly inflammatory bowel disease (IBD) or colon cancer. You should contact a doctor if you have any bleeding with bowel movements.

Sometimes an anal fissure may be a painless wound that won't heal and that bleeds intermittently but causes no other symptoms.

How is an anal fissure diagnosed?

Most doctors can diagnose an anal fissure from symptoms and by looking at the anus. Usually, the doctor can see the fissure by gently separating the buttocks.

A doctor may use a gloved finger (digital rectal examination) or a lighted instrument (anoscope) to examine the fissure. But if the fissure is extremely painful, the doctor will usually wait until it has begun to heal before performing a rectal examination or using an anoscope (anoscopy) to rule out other problems. A topical anesthetic may be used if an immediate examination is necessary.

During an examination, a doctor can also find out whether another condition may be causing the fissure. If you have several fissures or have one or more in an area of the anus where fissures usually do not occur, you may have another condition such as inflammatory bowel disease, syphilis, a suppressed immune system, tuberculosis, HIV infection, or anal cancer. Most fissures occur along the midline—the top or bottom—of the anus.

How is it treated?

Most acute fissures need some home treatment, including soaking in a shallow tub of warm water (sitz bath) 2 or 3 times a day, increasing fibre in the diet, and taking stool softeners or laxatives. Some people find relief in a day or two of home treatment. Although your pain may go away, it may take several weeks for the fissure to heal completely. Sometimes fissures heal without treatment.

Try to prevent constipation, because it can keep a fissure from healing. The pain of a fissure may make you anxious about having bowel movements. But trying not to have bowel movements will only increase constipation and create a cycle that keeps the fissure open and painful.

Drinking lots of water or other fluids also will make stools softer and easier to pass.

You may want to use a non-prescription ointment such as zinc oxide, Preparation H, or Anusol to soothe anal tissues. But evidence suggests that fibre and sitz baths help symptoms better than non-prescription creams.1 Talk with your doctor about whether you should use these medicines for a short period of time.

If a fissure lasts a long time, prescription medicine may help. Prescription medicines used to treat anal fissure include nitroglycerin, high blood pressure medicines, and botulinum toxin (Botox).

You may need to consider surgery if medicines do not stop your symptoms. The most commonly used surgery is lateral internal sphincterotomy. In this procedure, a doctor cuts into part of the internal sphincter to relax the spasm that is causing the fissure.

Learning about anal fissure:

Being diagnosed:

Getting treatment:


Most anal fissures cause:

  • A sharp, stinging or burning pain during a bowel movement. Pain from a fissure may be quite severe. It can be brief or last for several hours after a bowel movement.
  • Itching.
  • Bleeding, often a small spot of bright red blood on toilet tissue. Tell your doctor if you have any bleeding with a bowel movement.

An anal fissure can be a painless wound that won't heal and that bleeds intermittently but causes no other symptoms.

Examinations and Tests

Your doctor can diagnose an anal fissure from your symptoms and a physical examination. The examination may include:

  • Looking at the fissure by gently separating the buttocks.
  • Digital rectal examination. The doctor uses a gloved finger to feel structures in the anal canal.
  • Anoscopy. This examination involves using a short, lighted scope to look into the anal canal.

A doctor usually will wait until the fissure has begun healing before doing a digital rectal examination or anoscopy. If an examination needs to be done immediately, a topical anesthetic can be used to numb the area.

The location of a fissure is important in the diagnosis. If you have more than one fissure or have a fissure on the side of the anus (rather than at the top or the bottom), you may have another condition that is causing fissures. Possible conditions include inflammatory bowel disease (IBD), anal cancer, syphilis, tuberculosis, a suppressed immune system, or HIV infection.

A doctor may look for a small piece of loose skin (a skin tag) in the anus, often a sign of a long-term (chronic) fissure. Skin tags are often mistakenly identified as hemorrhoids.

Treatment Overview

Most short-term (acute) anal fissures can heal with home treatment in 4 to 6 weeks. Pain during bowel movements usually goes away within a couple of days of treatment.

Home treatment involves sitting in warm water (sitz bath) for 20 minutes 2 or 3 times a day, increasing fibre and fluids in the diet, and using stool softeners or laxatives to have pain-free bowel movements. Talk with your doctor about how long you should use laxatives.

Sometimes fissures do not heal with these remedies. A fissure that has not healed after 6 weeks is considered long-term, or chronic, and may need additional treatment.


Medicines are usually the first-line treatment for chronic fissures.

  • A 0.2% nitroglycerin cream can reduce the pressure in the internal anal muscle (sphincter) and allow the fissure to heal. A pea-sized dot of cream is massaged into the fissure and the surrounding area. Do not use a larger amount at one time, because this medicine can cause headaches, light-headedness, or fainting from low blood pressure. It is a good idea to either wear gloves when applying the nitroglycerin cream or wash your hands right after. The skin on your fingers can absorb the medicine and increase your chance of side effects.
  • The calcium channel blockers nifedipine and diltiazem also may help healing, also by reducing the pressure in the internal anal sphincter. These two medicines are available as pills. Also, they can be made into a gel that can be massaged into the fissure and the surrounding area. The pill form of these medicines has more side effects than the gel form.
  • Botulinum toxin (Botox) may be injected into the internal anal sphincter. Botox causes temporary paralysis of muscle, which can reduce muscle tension and help the anal fissure heal.
  • Hydrocortisone ointments are available by prescription and can soothe anal tissues. Talk to your doctor about this treatment.


Surgery may be done when more conservative treatments fail to heal an anal fissure.

The main surgery for chronic anal fissure is lateral internal sphincterotomy. The doctor makes a small incision into the internal anal sphincter to reduce anal resting pressure.

It is important to understand that, even with surgery, an anal fissure must heal on its own. A sphincterotomy involves operating on the sphincter muscles, not closing the actual fissure.

Lateral internal sphincterotomy has a better success rate than any medicine that is used to treat long-term anal fissures. The results last longer, and fewer people have anal fissures come back after surgery than after treatment with medicine.2

In some studies, a greater number of people who had lateral internal sphincterotomy had some inability to control gas or stool (incontinence) after surgery compared to people treated with medicine. Despite these results, satisfaction with this surgery is high. And a review of many studies showed that the risk of incontinence was 8%. This means that about 8 out of 100 people who had the surgery had some problem with incontinence. But this rate was not very different from the rates seen in people who were treated with medicine for their chronic anal fissures.3

Another study showed that lateral internal sphincterotomy was better than nitroglycerin cream at healing chronic anal fissures. And there was no difference in long-term continence between the people who used nitroglycerin cream and the people who had surgery.4

In some cases, the risk of incontinence is too great to justify doing lateral internal sphincterotomy. This may be true for women who develop a fissure while giving birth, because they typically do not have a high resting pressure in their internal sphincter. A procedure called anal advancement flap may be done instead of sphincterotomy. In this procedure, the edges of the fissure are removed, and healthy tissue is sewn over the area.

Home Treatment

Most short-term (acute) and a few long-term (chronic) anal fissures will heal with home treatment.

  • Avoid constipation:
    • Include fruits, vegetables, beans, and whole grains in your diet each day. These foods are high in fibre.
    • Drink plenty of fluids, enough so that your urine is light yellow or clear like water.
    • Get some exercise every day. Try to do moderate to vigorous activity at least 2½ hours a week.5 It's fine to be active in blocks of 10 minutes or more throughout your day and week.
    • Take a fibre supplement, such as Metamucil, every day if needed. Start with a small dose and very slowly increase the dose over a month or more.
    • Schedule time each day for a bowel movement. Having a daily routine may help. Take your time and do not strain when having a bowel movement.
  • Stool softeners or laxatives can make bowel movements more comfortable. Ask your doctor how long you should take laxatives.
  • Sitting in a tub filled with a few inches of warm water (sitz bath) for 20 minutes 2 or 3 times a day soothes the torn tissue and helps relax the internal anal sphincter. This may help heal the anal fissure.
  • You may want to use ointments or creams such as zinc oxide, Preparation H, or Anusol (which includes an anesthetic). But evidence suggests that fibre and sitz baths help symptoms better than non-prescription creams.1
  • Although some people may be tempted to use a mirror or have a family member examine a fissure, do not separate the buttocks. Doing so might slow healing of the fissure.
  • Instead of using toilet paper, use baby wipes or medicated pads, such as Tucks, to clean after a bowel movement. These products can be less irritating to an anal fissure.

Conservative treatment measures—including using stool softeners or bulking agents and taking regular sitz baths—allow about 9 out of 10 acute anal fissures to heal. And about 4 out of 10 long-term (or chronic) anal fissures will heal after conservative treatment is used.1

Other Places To Get Help


American College of Gastroenterology
P.O. Box 342260
Bethesda, MD  20827-2260
Phone: (301) 263-9000
Web Address:

The American College of Gastroenterology is an organization of digestive disease specialists. The website contains information about common gastrointestinal problems.

American Gastroenterological Association
4930 Del Ray Avenue
Bethesda, MD  20814
Phone: (301) 654-2055
Fax: (301) 654-5920
Web Address:

The American Gastroenterological Association is a society of doctors who specialize in the digestive system (gastroenterologists). This Web site can help you find a gastroenterologist in your area. They also have patient information on many gastrointestinal diseases and disorders.

American Society of Colon and Rectal Surgeons
85 West Algonquin Road
Suite 550
Arlington Heights, IL  60005
Phone: (847) 290-9184
Fax: (847) 290-9203
Web Address:

The American Society of Colon and Rectal Surgeons is the leading professional society representing more than 1,000 board-certified colon and rectal surgeons and other surgeons dedicated to treating people with diseases and disorders affecting the colon, rectum, and anus.

Canadian Society of Colon and Rectal Surgeons
Web Address:

The Canadian Society of Colon and Rectal Surgeons is a non-profit organization. A list of surgeons is available for patients.

National Digestive Diseases Information Clearinghouse (NDDIC)
2 Information Way
Bethesda, MD  20892-3570
Phone: 1-800-891-5389
Fax: (703) 738-4929
Web Address:

This clearinghouse is a service of the U.S. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the U.S. National Institutes of Health. The clearinghouse answers questions; develops, reviews, and sends out publications; and coordinates information resources about digestive diseases. Publications produced by the clearinghouse are reviewed carefully for scientific accuracy, content, and readability.



  1. Dozois EJ, Pemberton JH (2006). Anal fissure section of Hemorrhoids and other anorectal disorders. In MM Wolfe et al., eds., Therapy of Digestive Disorders, pp. 948–950. Philadelphia: Elsevier.
  2. Nelson R (2007). Anal fissure (chronic), search date January 2007. Online version of BMJ Clinical Evidence. Also available online:
  3. Nelson R (2006). Non-surgical therapy for anal fissure. Cochrane Database of Systematic Reviews (4).
  4. Brown CJ, et al. (2007). Lateral internal sphincterotomy is superior to topical nitroglycerin for healing chronic anal fissure and does not compromise long-term fecal continence: Six-year follow-up of a multicenter, randomized, controlled trial. Diseases of the Colon and Rectum, 50(4): 442–448.
  5. Canadian Society for Exercise Physiology (2011). Canadian Physical Activity Guidelines For Adults. Available online:

Other Works Consulted

  • Hull TL (2006). Anal fissure section of Diseases of the anorectum. In M Feldman et al., eds., Sleisenger and Fordtran's Gastrointestinal and Liver Disease, 8th ed., vol. 2, pp. 2840–2842. Philadelphia: Saunders Elsevier.
  • Madoff RD, Fleshman JW (2003). American Gastroenterological Association Medical position statement: Diagnosis and care of patients with anal fissure. Gastroenterology, 124(1): 233–234.
  • Nelson RL (2010). Operative procedures for fissure in ano. Cochrane Database of Systematic Reviews (4).
  • Welton ML, et al. (2010). Anal fissure and ulcer section of Anorectum. In GM Doherty, ed., Current Diagnosis and Treatment: Surgery. 13th ed., pp. 710–712. New York: McGraw-Hill.


By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Primary Medical Reviewer Anne C. Poinier, MD - Internal Medicine
Specialist Medical Reviewer C. Dale Mercer, MD, FRCSC, FACS - General Surgery
Last Revised November 18, 2010

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