An anal fissure, fissure in Ano or rectal fissure is a break or tear in the skin of the anal canal. Anal fissures may be noticed by bright red anal bleeding on toilet paper and undergarments, or sometimes in the toilet. If acute they may cause pain after defecation, but with chronic fissures, pain intensity is often less. Anal fissures usually extend from the anal opening and are usually located posteriorly in the midline, probably because of the relatively unsupported nature and poor perfusion of the anal wall in that location. Fissure depth may be superficial or sometimes down to the underlying sphincter muscle.
An anal fissure is a small tear in the thin, moist tissue (mucosa) that lines the anus. An anal fissure may occur when you pass hard or large stools during a bowel movement. Anal fissures typically cause pain and bleeding with bowel movements. You also may experience spasms in the ring of muscle at the end of your anus (anal sphincter).
Anal fissures are very common in young infants but can affect people of any age. Most anal fissures get better with simple treatments, such as increased fiber intake or sitz baths. Some people with anal fissures may need medication or, occasionally, surgery.
Causes of Anal Fissure
Most anal fissures are caused by stretching of the anal mucosa beyond its capability.
Superficial or shallow anal fissures look much like a paper cut, and may be hard to detect upon visual inspection, they will generally self-heal within a couple of weeks. However, some anal fissures become chronic and deep and will not heal. The most common cause of non-healing is spasming of the internal anal sphincter muscle which results in impaired blood supply to the anal mucosa. The result is a non-healing ulcer, which may become infected by fecal bacteria. In adults, fissures may be caused by constipation, the passing of large, hard stools, or by prolonged diarrhea. In older adults, anal fissures may be caused by decreased blood flow to the area. When fissures are found laterally, tuberculosis, occult abscesses, leukemic infiltrates, carcinoma, acquired immunodeficiency syndrome (AIDS) or inflammatory bowel disease should be considered as causes. Some sexually transmitted infections can promote the breakdown of tissue resulting in a fissure. Examples of sexually transmitted infections that may affect the anorectal area are syphilis, herpes, chlamydia and human papilloma virus.
Common causes of anal fissure include:
- Passing large or hard stools
- Constipation and straining during bowel movements
- Chronic diarrhea
- Inflammation of the anorectal area, caused by Crohn’s disease or another inflammatory bowel disease
- Childbirth trauma in women
- Sexual Activities
- Crohn’s disease
- ulcerative colitis
- poor toileting in young children.
Less common causes of anal fissures include:
- Anal cancer
Factors that may increase your risk of developing an anal fissure include:
- Infancy. Many infants experience an anal fissure during their first year of life; experts aren’t sure why.
- Aging. Older adults may develop an anal fissure partly due to slowed circulation, resulting in decreased blood flow to the rectal area.
- Constipation. Straining during bowel movements and passing hard stools increase the risk of tearing.
- Childbirth. Anal fissures are more common in women after they give birth.
- Crohn’s disease. This inflammatory bowel disease causes chronic inflammation of the intestinal tract, which may make the lining of the anal canal more vulnerable to tearing.
- Anal intercourse.
Anal fissures are common during infancy. 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 IBD, 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. People who frequently experience constipation are at an increased risk for anal fissures as well. Straining and passing large, hard stools are the most common causes of anal fissures.
Symptoms of Anal Fissure
People with anal fissures almost always experience anal pain that worsens with bowel movements. The pain following a bowel movement may be brief or long lasting; however, the pain usually subsides between bowel movements. The pain can be so severe that patients are unwilling to have a bowel movement, resulting in constipation and even fecal impaction. Moreover, constipation can result in the passage of a larger, harder stool that causes further trauma and makes the fissure worse. The pain also can affect urination by causing discomfort when urinating (dysuria), frequent urination, or the inability to urinate. Bleeding in small amounts, itching (pruritus ani), and a malodorous discharge may occur due to the discharge of pus from the fissure. As previously mentioned, anal fissures commonly bleed in infants.
Anal Fissure Diagnosis
If possible, your doctor will perform a digital rectal exam, which involves inserting a gloved finger into your anal canal, or use a short, lighted tube (anoscope) to inspect your anal canal. However, if this is too painful for you, your doctor may be able to diagnose an anal fissure only by observation.
An acute anal fissure looks like a fresh tear, somewhat like a paper cut. A chronic anal fissure likely has the tear, as well as two separate lumps or tags of skin, one internal (sentinel pile) and one external (hypertrophied papilla).
The fissure’s location offers clues about its cause. A fissure that occurs on the side of the anal opening, rather than the back or front, is more likely to be a sign of another disorder, such as Crohn’s disease. Your doctor may recommend further testing if he or she thinks you have an underlying condition:
- Flexible sigmoidoscopy. Your doctor will insert a thin, flexible tube with a tiny video into the bottom portion of your colon. This test may be done if you’re younger than 50 and have no risk factors for intestinal diseases or colon cancer.
- Colonoscopy. Your doctor will insert a flexible tube into your rectum to inspect the entire colon. This test may be done if you are older than age 50 or you have risk factors for colon cancer, signs of other conditions, or other symptoms such as abdominal pain or diarrhea.
A doctor can diagnose an anal fissure based on your symptoms and a physical exam. The exam may include:
- Looking at the fissure by gently separating the buttocks.
- A digital rectal exam. The doctor inserts a gloved finger into the anal canal.
- Anoscopy. This involves using a short, lighted scope to look into the anal canal.
The doctor may wait until the fissure has started to heal before doing a rectal exam or anoscopy. If an exam needs to be done right away, medicine can be used to numb the area.
During an exam, a doctor can also find out whether another condition may be causing the fissure. Having several fissures or having one or more in an area of the anus where fissures usually don’t occur can be a sign of a more serious problem, such as inflammatory bowel disease or a weakened immune system.
Anal Fissure Treatment
Anal fissures often heal within a few weeks if you take steps to keep your stool soft, such as increasing your intake of fiber and fluids. Soaking in warm water for 10 to 20 minutes several times a day, especially after bowel movements, can help relax the sphincter and promote healing.
If your symptoms persist, you’ll likely need further treatment.
Non-surgical treatments are recommended initially for acute and chronic anal fissures. These include topical nitroglycerin or calcium channel blockers (e.g. diltiazem), or injection of botulinum toxin into the anal sphincter.
Other measures include warm sitz baths, topical anesthetics, high-fiber diet and stool softeners.
Your doctor may recommend:
- Externally applied nitroglycerin (Rectiv), to help increase blood flow to the fissure and promote healing and to help relax the anal sphincter. Nitroglycerin is generally considered the medical treatment of choice when other conservative measures fail. Side effects may include headache, which can be severe.
- Topical anesthetic creams such as lidocaine hydrochloride (Xylocaine) may be helpful for pain relief.
- Botulinum toxin type A (Botox) injection, to paralyze the anal sphincter muscle and relax spasms.
- Blood pressure medications, such as oral nifedipine (Procardia) or diltiazem (Cardizem) can help relax the anal sphincter. These medications may be taken by mouth or applied externally and may be used when nitroglycerin is not effective or causes significant side effects.
If you have a chronic anal fissure that is resistant to other treatments, or if your symptoms are severe, your doctor may recommend surgery. Doctors usually perform a procedure called lateral internal sphincterotomy (LIS), which involves cutting a small portion of the anal sphincter muscle to reduce spasm and pain, and promote healing. Studies have found that for chronic fissure, surgery is much more effective than any medical treatment. However, surgery has a small risk of causing incontinence.
Surgical procedures are generally reserved for people with anal fissure who have tried medical therapy for at least one to three months and have not healed. It is not the first option in treatment.
The main concern with surgery is the development of anal incontinence. Anal incontinence can include inability to control gas, mild fecal soiling, or loss of solid stool. Some degree of incontinence can occur in up to 45 percent of patients in the immediate surgical recovery period. However, incontinence is rarely permanent and is usually mild. The risk should be discussed with one’s surgeon.
Surgical treatment, under general anaesthesia, was either anal stretch (Lord’s operation) or lateral sphincterotomy where the internal anal sphincter muscle is incised. Both operations aim to decrease sphincter spasming and thereby restore normal blood supply to the anal mucosa. Surgical operations involve a general anaesthetic and can be painful postoperatively. Anal stretch is also associated with anal incontinence in a small proportion of cases and thus sphincterotomy is the operation of choice.
Prevention of Anal Fissure
For adults, the following may help prevent anal fissures:
- Avoiding straining when defecating. This includes treating and preventing constipation by eating food rich in dietary fiber, drinking enough water, occasional use of a stool softener, and avoiding constipating agents. Similarly, prompt treatment of diarrhea may reduce anal strain.
- Careful anal hygiene after defecation, including using soft toilet paper and cleaning with water, plus the use of sanitary wipes.
- In cases of pre-existing or suspected fissure, use of a lubricating ointment (It is important to note that hemorrhoid ointment is contraindicated because it constricts small blood vessels, thus causes a decrease in blood flow, which prevents healing).
- 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 diarrhea immediately
- Changing diapers frequently (for infants)
In infants, frequent diaper change can prevent anal fissure. As constipation can be a cause, making sure the infant is drinking enough fluids (i.e. breastmilk, proper ratios when mixing formulas) is beneficial. In infants, once an anal fissure has occurred, addressing underlying causes is usually enough to ensure healing occurs.