Definition and Overview

Anal fissure, also known as fissure-in-ano, is a small tear in the lining of the thin moist tissue that lines the anus, causing pain during bowel movement. An anal fissure usually develops due to strain when passing large or hard stools. Although it causes pain and discomfort, an anal fissure usually don't lead to any serious problems. This condition can affect people of all ages, even healthy individuals. It is relatively common and accounts for 15% of the visits to a colorectal specialist. Anal fissures are quite common in young infants and seniors.

Anal fissures can be acute or chronic. Acute or short-term cases usually heal within a few days. Chronic fissures, those that usually don't heal within 8 to 12 weeks, usually need medical treatment.

Symptoms of Anal Fissure

Anal fissures can range from minor to severe. Usual symptoms include the following:

  • Itching (pruritus ani) in the anal opening
  • Bleeding (usually bright red blood) that is separate from the stool; you can often see small spots or a few drops of bright red blood on the toilet bowl
  • A sharp, burning or stinging sensation during defecation that can last for a brief moment or persist for several hours
  • A malodorous discharge from the anal opening (usually for severe cases) that may indicate possible infection
  • Frequent urination or inability to urinate

Some anal fissures are asymptomatic and painless. Bleeding can occur from time to time but with no other observed symptoms.

Causes of Anal Fissures

Anal fissures are typically caused by trauma or injury to the anal canal. This can occur when passing large stools, including cases of constipation. It can also be triggered by repeated diarrhea, causing irritation in the anal lining, or caused by a strain during childbirth. Fissures may also be caused by anal intercourse or a side effect of a rectal exam.

Experts believe that the actual trauma is due to the extra tension in the two muscular rings called sphincters that control the opening of the anus. The outer sphincter is a controlled muscle while the inner is an involuntary type. If the pressure in the area is heightened due to the aforementioned triggers, it can reduce the blood flow and cause a spasm, leading to a fissure. Continuous pressure and stress in the area can cause delays in the full recovery from a fissure.

Other diseases such as inflammatory bowel diseases (IBD) like Crohn’s disease and ulcerative colitis, as well as sexually transmitted infections like syphilis and herpes, may lead to anal fissures.

When to See a Doctor and Diagnosis

Anal fissures usually don't need immediate medical attention. In most cases, especially acute ones, the symptoms go away in a few days. However, if the symptoms have become chronic and the symptoms have worsened to affect normal defecation, you will need to consult your doctor as soon as possible.

During your consultation, your doctor will first rule out other conditions with similar symptoms, including hemorrhoids (swelling around the anus). Several tests will be performed depending on the severity of your symptoms. After asking questions regarding your medical history, a physical examination of the area or a digital rectal examination (colonoscopy or sigmoidoscopy) may be performed for severe cases. Your GP may also refer you to a colorectal specialist should the need arise.

Colon and rectal surgeons are experts in treating anal fissures and other colorectal and anal problems. These doctors have completed advanced surgical training for the treatment of these conditions, apart from their general surgical training. Licensed colorectal surgeons have to pass intensive examinations before they can perform colon and rectal surgeries.

Treatments for Anal Fissure

Almost all treatment options for anal fissure are aimed at breaking the strain and spasms in the anal sphincter to allow the muscles to relax. A pressure-free environment can promote faster healing for fissures. For acute cases, high fiber diet and fiber supplementation are usually recommended without any medical intervention. With a high-fiber diet, there can be less strain during bowel movement, allowing better chances for the anal fissure to heal fast. You will also be asked to avoid certain foods such as nuts, popcorn and chips that are hard to digest. Increasing water or liquid intake can also go a long way in healthy and frequent bowel movement. Home remedies like lukewarm tub baths (Sitz baths) and warm compresses for 10-20 minutes several times a day will help relax the spasms and increase blood flow, which may help shorten healing times.

For chronic anal fissures, topical anesthetics such as lidocaine, xylocaine and pramoxine may be recommended prior to defecation to reduce and manage pain. Steroids are usually included in these anesthetic formulations to reduce the inflammation caused by the fissure. Ointments containing nitroglycerin may also be recommended to relax the spincture muscles and promote healing. Creams or ointments with calcium channel blocking drugs (CCBs), which work similar to nitroglycerin but with less side effects, may also be recommended.

Meanwhile, serious cases of anal fissure usually require surgical intervention. Colorectal surgeons inject Botulinum toxin (Botox) into the anal sphincter (an out-patient procedure called sphincterotomy) to promote relaxation of the anal sphincter and decrease pain and spasms, allowing the area to heal. The surgeon will first discuss potential risks of sphincterotomy and determine whether it is the best treatment for your particular situation. Recovery from surgical treatments for anal fissure take about 6 to 10 weeks, but patients can usually resume daily activities within a few days.

Fissures however, can easily recur should another trauma triggers it. It is then very important to continue with a high-fiber diet and good bowel practices even after the symptoms have subsided. If the problem worsens with time, further reassessment may be necessary to rule out other more serious colorectal problems.


  • Valente, Michael A., DO. American Society of Colon and Rectal Surgeons (2012). “Anal Fissure.” Available:
  • 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.
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