An anal fissure is a small tear or crack in the lining of the anus. It may occur when passing large or hard stools, straining during childbirth, or experiencing bouts of diarrhoea.
An anal fissure can cause sharp pain and bleeding during and after bowel movements. It may also cause itching and burning in the anal area.
An anal fissure is usually a minor condition that goes away within six weeks.
In most cases, the tear heals on its own within four to six weeks. Certain treatments can help relieve discomfort, including stool softeners and topical pain relievers. If an anal fissure doesn’t improve with these treatments, surgery may be required or your doctor may need to look for other underlying disorders that can cause anal fissures.
An anal fissure may cause one or more of the following symptoms:
- A visible tear in the skin around the anus
- A skin tag, or small lump of skin, next to the tear
- Sharp pain in the anal area during bowel movements
- Streaks of blood on stools or on tissue paper after wiping
- Burning or itching in the anal are
An anal fissure most often occurs when passing large or hard stools. Chronic constipation or frequent diarrhoea can also tear the skin around the anus. Other common causes include:
- Crohn’s disease or other inflammatory bowel diseases
- Straining during childbirth
- Decreased blood flow to the anorectal area
- Overly tight or spastic anal sphincter muscles
In rare cases, an anal fissure may develop due to:
- Anal cancer
Who is at risk of an anal fissure?
People who frequently experience constipation are at an increased risk for anal fissures. Older adults are also prone to anal fissures due to decreased blood flow in the anorectal area. During and after childbirth, women are at risk for anal fissures due to straining during delivery.
People with inflammatory bowel diseases, such as Crohn’s disease, also have a higher risk of developing anal fissures. The inflammation that occurs in the intestinal lining makes the tissue around the anus more prone to tearing.
How is an anal fissure diagnosed?
A doctor can usually diagnose an anal fissure simply by examining the area around the anus. However, they may want to perform a digital rectal exam to confirm the diagnosis. During this exam, the doctor will insert an endoscope or anoscope into your rectum to make it easier to see the tear. These medical instruments are thin tubes with attached cameras and lights that allow doctors to inspect the anal canal. Using an anoscope may also help your doctor find other causes of anal or rectal pain such as haemorrhoids.
How is an anal fissure treated?
Most anal fissures don’t require extensive treatment. However, certain home remedies can help promote healing and relieve uncomfortable symptoms. You can treat an anal fissure at home by:
- Using over-the-counter stool softeners
- Taking fibre supplements and increasing intake of fibrous foods, such as raw fruits and vegetables
- Taking warm baths called Sits baths to relax the anal muscles, relieve irritation, and increase blood flow to the anorectal area
- Applying a nitroglycerin ointment, such as Cortisone-10, to the anus to promote blood flow to the area and promote healing
- Applying topical pain relievers, such as Anusol-HC and Lidocaine, to the anus to ease discomfort
Your doctor may also suggest a brand of calcium channel blocker ointment that can relax the sphincter muscles and allow the anal fissure to heal.
Another possible treatment is Botox injections into the anal sphincter. The injections will prevent spasms in the anus by temporarily paralyzing the muscle. This allows the anal fissure to heal while preventing new fissures from forming.
If your anal fissure fails to respond to other treatments, your doctor may recommend an anal sphincterotomy. This is a surgical procedure that involves making a small incision in the anal sphincter to relax the muscle, which allows the anal fissure to heal. This is likely to be considered if less invasive therapies have failed.
Not all anal fissures are a sign of low-fibre diets and constipation. Poorly healing fissures or those located in a position other than the posterior and midline portion of your anus may indicate an underlying disease such as tuberculosis, HIV, or rectal cancer.
An anal fissure can’t always be prevented, but you can reduce your risk of getting one by taking the following preventive measures:
- Keeping the anal area dry
- Cleansing the anal area gently with mild soap and warm water
- Avoiding constipation by drinking plenty of fluids, eating fibrous foods, and exercising regularly
- Treating diarrhoea