An anal fissure is a small tear of your skin just inside the opening of your anus. They are very common in people of all ages, but are most common in teenagers and young adults. They can be very painful, especially when opening your bowels (passing motions). The fissure may bleed a little and stain the toilet paper with bright red blood after opening your bowels. An anal fissure will usually heal on its' own, but this often takes several weeks. The fissure may not heal and may become chronic. This is because the blood supply may be reduced to the skin of your anus due to the muscles tightening An anal fissure is a tear on the skin at the anal verge or just inside the opening of your anus. They are very common affecting all age groups but most common teenagers and young adults.

Symptoms:

A tearing pain often described as knife like on passing motions or defaecating
Blood on stool and toilet tissue after wiping
Constipation

Causes:
Constipation results in large hard stools passing through the anus when the anal muscles are contracting resulting in a tear of the skin at the anal opening. The blood supply to this area may be reduced due to tightening of the anal muscles.
Pregnancy can cause constipation which can have a similar effect.
Other serious conditions such as cancer of the rectum and anus, colitis can cause fissures although uncommon.

Diagnosis:
A good history usually makes the diagnosis. On examination there may be a skin tag also known as sentinel tag seen at the anal verge in relation to the fissure. Rectal examination is not usually tolerated by patients with anal fissure.

Treatment:
In a majority of the patients the fissure is self limiting and will heal by itself without any treatment.

Regular pain killers and keeping the motions soft with tablets will help in the healing process. It is important to avoid very spicy food and pain killers which cause constipation. You should drink a lot of water as this will help to keep your motions soft.

Local anaesthetic ointments applied on and around the fissure may help to reduce the pain If the fissure is resistant to treatment with simple measures,
Glyceryl Trinitrate Ointment can be used to help with healing. This ointment relaxes the muscles in the anus thus promoting blood supply to the skin I the anus and aids with healing of the fissure. Alternative medications are available but should be taken only on the advice of a specialist.

Chronic fissures which are resistant to the above treatments should be treated by surgery. This is usually achieved by cutting small portion of the inner muscle around the anus (Internal sphincterotomy). These procedures are carried out in hospital under general anaesthetic. Surgery is very effective, but carries a small risk of some degree of incontinence (of faeces or wind), although this may improve with time.