What is an Anal Fissure?
An anal fissure is a tear in the lining of the back passage. This is situated in the anus and is usually at the back (in the direction of the spine) but can be in the front (1%). It is usually 1 to 2 centimetres long and runs in a vertical direction.
Although it can occur in certain diseases, it is usually brought on by a combination of factors. These are: family tendency, constipation, sitting too long on the toilet (longer than 2 minutes) and stress. The fissure usually passes through phases when it gives a lot of trouble and when it is quiescent and without treatment can be a life long problem. It is usually associated with an external lump of skin at the anus which the patient feels is the cause of the problem and which is called the sentinel tag.
A fissure commonly gives pain with bowel movements, can give discomfort on exercise or walking, and causes spasm of the internal sphincter, which can result in thrombosis of haemorrhoids as well as gas discomfort in the abdomen. In addition it can act as a portal for infection and can cause alarming bleeding.
Fissure is often associated with haemorrhoids.
Treatment of fissure is often prolonged and it is important to heal it completely or it comes back. Even after it is healed the tissue takes time to regain its strength (three months for 40% and two years for 80% of previous strength) so care must be taken to avoid constipation or straining for a long time after healing.
The first line treatment is the use of an ointment containing Nitro-glycerin (the same medicine used for the heart). This works by relaxing the muscle from its spasm around the anus and also by increasing the blood supply to the scarred fissure.
If the fissure has been present for a short time, it will heal quickly, but if present for a long time it may require the ointment for months.
The ointment is applied in a pea-sized lump on a gloved finger, which is fully inserted into the anus and applied to the fissure three times a day.
At the beginning, the ointment is absorbed into the blood stream and can give rise to a headache or rapid pulse. If this happens, use less ointment, but more often – say three or four times a day. Although 2% ointment has been used, we use a more dilute ointment (0.13%), which has much less of these side effects. Sometimes we use another ointment – Diltiazem (an ACE inhibitor)- that doesn't give headaches but this takes longer to heal the fissure. After healing, the ointment must be continued for 3 - 6 months to avoid recurrence.
The ointment must be supplemented by standard bowel care. Use a sitz bath (soaking in a warm tub with a tablespoon of ordinary salt in the water) or use a bidet if you have one for cleansing the area after every bowel movement.
To avoid constipation take daily two tablespoons of natural oat bran (alternatives are the same amount of natural wheat bran, psillium, Metamucil or other soluble fibre) and make sure you drink 7 to 8 glasses of water daily.
Try not to sit longer than 2 minutes on the toilet – if you can't have a bowel movement come back in a few hours when you are ready.
Rarely the fissure does not respond to this management and Botox can be used to reduce spasm and supplement the treatment (it is expensive from the Pharmacy), or surgery (a small but definite risk of loss of control of bowel movements).