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An anal fissure is an anal tear or crack, in the lining of the anal canal, a cut or tear in the anus that extends into the anal canal.
It can cause pain during and after a bowel movement and there may be blood in the stool.
Most anal fissures are less than one centimeter across, but the anus is a highly sensitive part of the body. As a result, a pain in this region can be quite severe, even with a small tear.
In this article we will cover the symptoms, diagnosis, and treatment of anal fissures, and cover way in which they can be prevented.
Here are some key points about anal fissures. More detail and supporting information is in the main article.
- damage to the lining of the anus is a common cause
- in some cases they are idiopathic (no known cause)
- approximately 10 percent of people are affected in their lifetime
- staying hydrated may help prevent anal fissures
The main signs and symptoms of an anal fissure include:
Pain – especially when passing stools. During the passing of a stool the pain is sharp, and then afterward there may be a longer deep burning sensation. Fear of pain may put some patients off going to the toilet, increasing their risk of constipation.
If the person delays using the bathroom, this can make the pain and the tear worse, because the stools will be harder and larger. Some people may experience a sharp pain when they clean themselves with toilet paper.
Blood – because the blood is fresh, it will be bright red and may be noticed on the stools or the toilet paper. Anal fissures in infants commonly bleed.
Itching – in the anal area. The sensation may be intermittent or persistent.
Dysuria – discomfort when urinating (less common). Some patients may urinate more frequently.
Anal fissure can happen for a number of reasons.
- Constipation – large, hard feces (stools) are more likely to result in lesions in the anal area during a bowel movement than soft and smaller ones.
- Diarrhea – repeated diarrhea can cause an anal fissure to develop.
- Muscle spasms – experts believe that anal sphincter muscle spasms may increase the risk of developing an anal fissure. A spasm is a brief, automatic jerking muscle movement, when the muscle can suddenly tighten. Muscle spasms may also undermine the healing process.
- Pregnancy and childbirth – pregnant women have a higher risk of developing an anal fissure towards the end of their pregnancy. The lining of the anus may also tear during childbirth.
- STIs (sexually-transmitted infections) – also known as STDs (sexually transmitted diseases) are linked to a higher risk of having anal fissures. Examples include syphilis, HIV, HPV (human papillomavirus), herpes and Chlamydia.
- Underlying conditions – some underlying conditions, such as Crohn’s disease, ulcerative colitis, and other inflammatory bowel diseases may cause ulcers to form in the anal area.
- Anal sex – can in rare instances cause anal fissures.
Two muscular rings (sphincters) control the anus – the outer ring is consciously controlled; the inner ring is not. The inner sphincter is under constant pressure. Experts believe that, if the pressure gets too much, the inner sphincter might spasm, reducing blood flow, increasing the risk of a fissure.
Anal fissures can affect people of any age or sex equally. It is the most common cause of rectal bleeding in babies and children. Some children may find the sight of bright red blood in stools and toilet paper distressing.
In most cases, anal fissures resolve without the need for medical treatment or surgery. Topical creams, suppositories, or both, and OTC painkillers may help with symptoms. Some people, however, may experience chronic problems if the lesion fails to heal correctly.
An anal fissure that lasts less than 6 weeks is called an acute anal fissure. A chronic anal fissure has symptoms for longer than 6 weeks. A primary anal fissure has no identifiable cause, while a secondary anal fissure does have an identifiable cause.
In most cases, an anal fissure will resolve itself within a few weeks. The doctor may recommend some medications to relieve symptoms of pain, burning, or discomfort. If the patient is suffering from constipation, a laxative may be prescribed.
The individual will also be encouraged to increase their dietary fiber intake, which will help soften the stools. The National Health Service (NHS), United Kingdom, says that adults should aim for at least 18 grams of fiber each day.
There is a risk of stomach cramps, wind, bloating, and diarrhea if the fiber intake increase is rapid and too high.
The increase should be done gradually.The patient should make sure they are drinking plenty of fluids, preferably water.
The doctor may recommend a topical anesthetic. Topical means it is applied directly to the skin. For the prolonged burning sensation after going to the toilet, Tylenol (acetaminophen) or ibuprofen may help (patients should ask their doctors for guidance). Some patients find that a warm (not too hot) bath helps relax the muscles and ease the pain.
Topical nitroglycerin medication helps speed up lesion healing by dilating the blood vessels in the area. A doctor may prescribe this medication if healing is slower than expected.
Calcium channel blockers
A medication originally designed to bring down high blood pressure; it also relaxes the sphincter muscle, as well as increasing the supply of blood to the affected area, which speeds up healing.
A steroid cream/ointment
This will reduce inflammation around the lesion, which may help with symptoms of itching and pain.
Botulinum toxin (botox)
Used successfully for many disorders with muscle spasms.
If the fissure is chronic (long-term) and does not heal, surgery may be an option.
A portion of the anal sphincter muscle is surgically removed, resulting in fewer and less severe spasms – this procedure is known as Internal sphincterotomy.
A fissurectomy is the surgical removal of the fissure – this procedure is rare and may be used in children.
The following are tips for preventing an anal fissure:
- Keep stools soft – eat a well-balanced diet with plenty of fiber. Make sure fluid/liquid intake is adequate – remember that water is the best fluid.
- Don’t delay using the bathroom – waiting means that when stools eventually come through, they will be larger and harder.
- Babies – frequent diaper changes can reduce the risk of anal fissures developing in babies.
- “Sharp” foods – avoid foods that may not be well-digested, such as nuts and popcorn.
- Wiping – if an individual is susceptible, using moistened cloths or cotton pads to clean after using the bathroom can help. Avoid rough or perfumed toilet paper.
- Exercise – regular exercise can reduce the risk of developing constipation, resulting in less risk of anal fissures. Stay well hydrated during and after exercise.
- Straining – avoid straining and sitting on the toilet for a long time.
A doctor will usually be able to diagnose an anal fissure after a physical examination of the anal area. If nothing is visible, gentle pressure onto the anal area will often result in pain if there is an anal fissure.
A rectal exam involves inserting a gloved finger or small instrument into the rectum. Usually, however, the doctor will not do this because it may cause too much pain. A specialist may apply anesthesia to the area before a rectal exam.
If the doctor suspects there may be something more serious, the patient will be referred to a specialist.
Sigmoidoscopy or colonoscopy
A rigid or flexible viewing tube is used to inspect inside the anus and rectum. This diagnostic test may be ordered if the doctor wants to rule out a more serious disease of the anus.