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What is an Anal Fissure?
An anal fissure is a tear in the lining of the anus which is called the mucosa. These affect about 1 in 10 people of all ages, but children and adults under 30 are more commonly diagnosed with this condition.
An anal fissure can appear suddenly. If it is present for less than six weeks it is called an “acute” fissure. If it is present for longer than this it is known as a “chronic” fissure.
What causes Anal Fissures?
Fissures may be caused by constipation and the passage of hard stool. However they may also be caused by diarrhoea and the passage of frequent stool.
Rarer causes include:
- Inflammatory bowel disease (IBD), such as Crohn’s disease and ulcerative colitis.
- Pregnancy and childbirth
- Sexually transmitted infection, such as syphilis or herpes which can infect the lining of the anal canal.
- In some cases, no clear causes can be identified.
What are the symptoms of Anal Fissures?
Most patients experience pain in the bottom which is experienced on defecation. This is usually quite intense and is commonly described as “like passing shards of glass”. Pain may persist for several hours after passing stool.
There may be bleeding on passing stools. If present, it is seen as bright red blood on the stool or toilet paper.
How is an Anal Fissure diagnosed?
Most are diagnosed by taking a careful history and by examining the bottom. Sometimes this requires an internal examination, although if there is pain this may not be attempted.
It is important for the doctor to rule out other causes of pain, and your doctor will recommend the best way to do this.
How are Anal Fissures treated?
1. Life style and toilet habit
If you are constipated you need to increase the amount of fibre in your diet, which means eating enough fruit and vegetables. You should exercise regularly and drink enough water.
It may also mean that you need some laxatives. It is important that you avoid straining or spending more than a few minutes on the toilet.
Take simple pain relief such as paracetamol before you open your bowels. Avoid using fragranced wet wipes. Regularly washing the area with plain water will also help.
2. Medical treatment
Your doctor may recommend the application of an ointment. This is 0.2% GTN (glyceryl tri-nitrate), which may give you a headache as a side effect which can be relieved by taking paracetamol half an hour before using the cream. GTN cream works by dilating the blood vessels in the anus, which promotes healing and relives spasm within the anal canal.
Second line treatment is a cream called Diltiazem, which may cause an itchy bottom. Typically treatment will be needed for 6 to 8 weeks, and occasionally a second course of treatment is needed.
About 7 out of 10 patients will get better with these simple measures.
If you don’t recover your doctor may recommend a Botox injection. This is typically given under general anaesthetic. It works by paralysing one of the muscles in the bottom, which eases spasm and promotes blood flow to the injured area. The medicine lasts for three to four months and then wears off. It is safe, with limited side effects. However, Botox will only work in about 50% of cases and there is a risk of temporary incontinence or infection or the need for further treatment.
Surgery is reserved for patients in whom these simple measures don’t work. This is known as a “lateral sphincterotomy”. The aim is to cut one of the muscles in the bottom and to permanently reduce the spasm in the anal sphincter muscles. It works in about 90% of patients. This is performed under general anaesthetic as a day case procedure. Most patients will recover in about two to four weeks. Although effective, 1 in 20 patients will experience some symptoms of incontinence. This is usually to wind or liquid motions and in most cases this is temporary.
Very resistant or chronic fissures may require more complex treatment with surgery called “advancement flaps”. This procedure creates a flap of healthy tissue which is taken from the skin around the bottom which is then stitched over the area of the fissure. This is a complex procedure which requires discussion with your surgeon.