What is an anal fissure?
An anal fissure is a very common condition where there is a painful tear in the lining of the anus, the opening where feces is excreted. It is often described as feeling like passing broken glass.
Typical symptoms are a sensation of tearing, ripping or burning and usually a small amount of bright red bleeding during and after a bowel movement. While the condition can be very painful, it is not usually serious.
Some studies estimate that about one in 10 people may have an anal fissure in their lifetime, though it is not possible to establish a precise figure, because some people may be too embarrassed to discuss the condition with their healthcare provider, and it is often misattributed to hemorrhoids.
Treatment consists in softening the stool, avoiding constipation and practicing good hygiene. Most anal fissures will heal within six weeks. An anal fissure that lasts for more than six weeks is called a chronic anal fissure. Occasionally, surgery is required to repair the tear.
Both males and females can be affected and, while anal fissures may occur at any age, they are primarily seen in young adults.
- A sharp, searing or burning pain in or around the bottom, which tends to be worse when passing feces and for about an hour or so afterwards
- Some bleeding, usually bright red on the toilet paper or stool
Good to know: A person with an anal fissure often puts off defecation, leading to a worsening cycle in which stools dry and harden, leading to further constipation and anal pain.
- Spasms or a tightening feeling in the anus when feces is excreted
- A sentinel pile, a tag of skin which sometimes develops on the edge of the anus, below the fissure
- Abscesses, a painful boil-like swelling near the anus filled with pus, which may lead to a fistula, a connection to the external skin, which may have a foul-smelling mucus discharge
Anal fissure causes
An anal fissure can occur when there is overstretching of the anal canal, which causes the lining to tear. Subsequent defecation stretches the area, meaning that healing is hindered. The anal sphincter may spasm as a result of anal fissure, restricting blood supply to the area and further hindering the healing process. In children especially, putting off defecation to avoid the associated pain may worsen constipation and exacerbate the problem.
Anal fissure may be classed as:
- Acute anal fissure, which clears up within six weeks. This is the most common type, and normally appears as linear with clear edges.
- Chronic anal fissure, which persists for more than six weeks. Chronic anal fissure healing time varies. Without treatment, it is possible to have an anal fissure for years.
A chronic fissure is usually deeper than an acute anal fissure and is often associated with an external skin tag. Chronic fissure is usually treatable, but recurrence of the fissure after treatment is common.
An anal fissure may also be classed as:
- Primary: having no apparent cause
- Secondary: due to an underlying condition, such as constipation, or resulting from pregnancy or childbirth
- Not eating enough fiber
- Not drinking enough fluids.
- Some medications, particularly strong painkillers, such as opioids.
- Not exercising or being less active
- Frequently ignoring the urge to defecate
- Changing diet or daily routine
- Anxiety or depression
- Some medical conditions, such as an underactive thyroid gland
For information about persistent constipation and its possible treatments, see this resource on chronic idiopathic constipation.
Anal fissure postpartum
Anal fissure can occur in pregnancy. During pregnancy, women often experience constipation due to the increased weight of the baby putting pressure on the rectum, the final segment of the digestive system, which stores feces until a person is ready to defecate.
Childbirth causes anal fissure in about one in 10 women.
Other anal fissure causes
- Persistent diarrhea
- A sexually transmitted infection, such as anal herpes, which causes the tissues to become soft and fragile
- Inflammatory bowel disease (IBD), such as ulcerative colitis or Crohn's disease
- Trauma, for instance from anal intercourse or other insertion of foreign objects
- Unusually tight anal sphincter muscles
Often, no clear cause for anal fissure can be found. They are associated with tight anal sphincter muscles, though the cause of this is unknown.
Anal fissure diagnosis
A doctor may diagnose anal fissure based on description of the symptoms and a physical examination.
The physical examination usually involves gently separating the buttocks to allow a doctor to see the area around the anus.
Most fissures appear in the 12 or 6 o’clock position. Those in other locations are likely to be associated with an underlying disorder, such as Crohn’s disease.
A doctor will usually avoid inserting anything into the anus, such as a gloved finger or small instrument, as this can cause substantial pain and is often unnecessary for provisional diagnosis.
Anal fissure anoscopy, sigmoidoscopy and colonoscopy
If the diagnosis is unclear, an anoscopy may be recommended. This involves inserting a thin, flexible tube with a light and camera on the end into the anus to look for symptom causes in the intestine. However, anoscopy is avoided in cases of an acute anal fissure as it is normally not well tolerated. Often, the patient is at first treated solely on the basis of symptoms. Sometimes, topical anaesthetic is used to facilitate an anoscopy.
Those who have a chronic or recurrent anal fissure after surgical therapy may be evaluated further with anoscopy and sigmoidoscopy, a procedure similar to anoscopy, but which also examines the lower colon.
Sometimes, a colonoscopy procedure is used to look for the presence of an underlying condition that may be causing an anal fissure, such as irritable bowel syndrome (IBD). This is similar to an anoscopy and sigmoidoscopy, but which also examines the entire colon.
See this resource for information on preparing for a colonoscopy.
Good to know: Anal fissures are sometimes misdiagnosed as hemorrhoids, delaying appropriate treatment, which may lead to an acute fissure becoming a chronic one, which is more difficult to treat. Wrong diagnosis of anal fissure may also allow other conditions to go undetected and untreated, such as infection and, though it is rare, anal cancer.
Anal fissure treatment
Treatment of an anal fissure primarily aims to ease the pain
Treatment begins with changing to a high-fiber diet, as well as maintaining sufficient fluid intake to soften feces and prevent further damage to the area while the wound is healing. Pain medication will also be given.
Usually, an anal fissure will heal with home treatment. In the case of chronic anal fissure, occasionally surgery will be recommended.
Anal fissure medicine
Anesthetic cream or ointment
This should be applied before going to the toilet. Anesthetic creams and ointments can be obtained by prescription, though some products are available without. Anesthetic should only be used for short periods of up to about five to seven days, otherwise the skin around the anus may become irritated.
Steroid cream or ointment
Steroids may be recommended to ease swelling if it is severe. This may help to relieve pain and any itching. Steroids should not be used for more than one week at a time.
Ibuprofen and paracetamol can help to ease pain. Opioids should be avoided, as this can cause constipation.
An anal fissure will heal more easily if feces is kept soft, so that it can pass more easily. A diet involving plenty of high fiber foods will help, such as fruit, vegetables, whole grains, nuts and seeds.
Stool softening medication may also be obtained on prescription or bought at pharmacies.
Glyceryl trinitrate (GTN) ointment
These medications may be prescribed for chronic anal fissures, present for six weeks or more. This is applied to the skin to reduce the anal sphincter pressure and can decrease pain and facilitate further healing. Side effects include headache, so the correct amount must be used.
Anal fissure home treatment
- Washing the area carefully with water after using the toilet, to avoid irritation and infection. Soap should be avoided as this may cause irritation, and the area should be gently dried.
- Sitz baths for anal fissure may be recommended as they are thought to soothe and relax the anus muscles, relieving some of the painful internal sphincter muscle spasm. This involves sitting in plain, non-soapy water after defecation.
- Eating plenty of fiber, such as is found in fruit, vegetables, cereals, wholemeal bread
- Drinking plenty of liquids to soften stools. Adults should aim to drink two litres or more each day. It is best to avoid alcoholic drinks as they can cause dehydration.
- Not putting off defecation, which can lead to bigger and harder stools forming, which may exacerbate the problem
Anal fissure surgery and injections
Also known as botox, this compound, which temporarily paralyzes muscles for up to three months, can be injected into the anal sphincter. This may be done without anesthesia or sedation. This may lead to temporary, mild anal leakage of gas or feces.
The surgery recommended for treating an anal fissure is normally sphincterotomy, which aims to relax the anal sphincter by cutting the muscle in order to loosen the anal muscle, therefore improving blood supply and aiding healing. Incontinence is a possible complication from surgery, so it is only offered to people whose symptoms have persisted despite medicine for at least one to three months. Anal fissure surgery recovery time varies from person to person.
Anal fissure complications
- Anal fistula, a small tunnel that develops between the end of the intestine and the anus
Anal fissure in babies and children
Anal fissures may also occur in children of any age, but are most common in toddlers. The child may scream when defecating and have bright red blood in their feces.
A common problem of anal fissure in children is that they will often deliberately avoid defecating, which may cause hardening of feces, leading to repeated re-tearing of the old fissure and preventing healing.
Even once the fissure has healed, a child may still be fearful of defecating. To break this cycle, it is important to give the child both feces-softening medication and laxatives to ensure regular defecation. The correct dose varies from child to child and may be gradually adjusted so that the child consistently produces large, soft feces.
Good to know: Rarely, anal fissures in children could indicate sexual abuse, especially if other causes such as hard feces are not present.
Anal fissure FAQs
Q: Are there home remedies for anal fissure?
A: Yes, there are several measures for home treatment which may help. These include:
- Sitz bath or hip bath, which involves sitting in plain, non-soapy water after defecation to keep the area clean
- Sitting on a warm heating pad or warm water bottle is thought to promote healing as heat increases blood flow to the area
However, medical attention should always be sought where there is bleeding from the anus. It may indicate other conditions which must receive prompt treatment to ensure the best outcome, such as anal cancer.
Q: Anal fissure or herpes - which do I have?
A: It is possible to get Herpes, a sexually transmitted infection, in the anal area. This can bring about what feels like a fissure around the anus and may be mistaken for one. Anal fissure causes burning pain and bleeding during defecation. Herpes causes blisters, itching and pain around the anus, but not especially while defecating, and lesions from herpes are unlikely to bleed.
Herpes may cause flu-like symptoms and other associated problems such as pain with urination. Anal herpes normally has a history of sexual exposure to the herpes virus.
BMJ Best Practice. "Anal fissure - Symptoms, diagnosis and treatment." Accessed 29 June 2018. ↩ ↩
UpToDate. "Anal fissure: Clinical manifestations, diagnosis, prevention." 9 December 2017. Accessed 29 June 2018. ↩
BMJ Best Practice. "Anal fissure - Symptoms, diagnosis and tòeatment." Accessed 29 June 2018. ↩