An anal fissure is a tear in the skin of the anus. This tear can cause severe pain on opening the bowels – pain which can last for some time after the bowel movement. It may be associated with a little bright blood from the bottom, and is often associated with some skin heaped up around the fissure from the tear – called a sentinel tag.

What causes anal fissures?

It is thought that a combination of strenuous straining on the toilet, hard solid faeces, spasm of the anal muscles and reduced blood flowing to the anal tissues all contribute to fissure formation, and prevent natural healing of the anal tear. Sometimes fissures occur during childbirth or with significant diarrhoea. Very complex fissures can be associated with other bowel conditions such as Crohn’s disease, a chronic inflammatory bowel condition.

What is the treatment for a fissure?

In the early phase, fissures can be treated with creams and ointments to sooth the tear. It is important to eat a high fibre diet and drink plenty of water, in order to maintain a soft, mushy regular stool which is easy to pass and prevents straining.

Diltiazem cream:

If the above simple measures have not improved your symptoms, Mrs Badvie will prescribe 2% diltiazem cream which is to be applied to the anus twice a day, ideally after a bowel movement, for six weeks. This cream helps to improve the blood flow to the anal tissues which promotes healing. 60-70% of patients will derive some benefit from this cream and in those patients, a second six-week course if often helpful to heal the fissure without the need for surgery.

Examination under anaesthesia and injection of Botox:

Where diltiazem cream has not been helpful, Mrs Badvie recommends an examination of the anus and rectum under anaesthesia (EUA) and injection of Botox into the internal anal muscle, which can be performed with removal of the fissure and the associated sentinel tag.

This is the first-line surgical treatment, and is an operation performed under general anaesthesia (so you will be entirely asleep), and usually as a day case (you will be discharged home the same day). First, Mrs Badvie performs a full examination of the anus and rectum to confirm the diagnosis once the anal muscles are relaxed and no longer painful. She then injects Botox into the internal anal sphincter muscle. Botox works by relaxing the anal muscles to allow improved blood flow and reduction in spasm. It is active for 3 months, which is usually long enough for the fissure to heal. It is 60-70% effective in fissure healing. Whilst the anal muscles are relaxed, it is possible to have a little anal leakage without noticing. This is temporary and lasts only 3 months whilst the Botox is working. Normal anal tightening and function will return.

At the end of the operation, Mrs Badvie administers local anaesthetic (a ‘pudendal nerve block’) to reduce any pain on awakening from the general anaesthetic.

Usually, one course of Botox treatment is enough, although occasionally two treatments are required, a minimum of 4 months apart to allow for maximal healing effect of the first dose.

Lateral sphincterotomy:

This is the traditional operation for anal fissures, and is still appropriate in a small number of cases where Botox has not been effective. Here, Mrs Badvie first performs a full examination of the anus and rectum under general anaesthesia. She places an incision (cut) in the internal anal sphincter, ‘tailored’ in length to the individual fissure. This opens and relaxes the sphincter muscles and is effective in healing the fissure in over 90% of cases. The high success rate of this operation, however, comes at the expense of a permanent small leakage in a few patients and therefore Botox, with only temporary leakage effects, is the preferred first treatment for many people.

At the end of the operation, Mrs Badvie administers local anaesthetic (a ‘pudendal nerve block’) to reduce any pain on awakening from the general anaesthetic. This operation is usually performed as a day case procedure, so you are likely to go home the same day.

After the operation

After any operation for fissures, it is vital to eat a high fibre diet and drink plenty of fluids, to maintain a soft, mushy regular stool which is easy to pass, in order to prevent straining. This promotes fissure healing and reduces the chance of any fissure returning in the future.

Mrs Badvie provides her expert opinion to help Bupa produce up-to-date and informative guidance for patients seeking advice and answers to questions on anal fissures and treatments:

https://www.bupa.co.uk/health-information/digestive-gut-health/anal-fissure

https://www.bupa.co.uk/health-information/digestive-gut-health/anal-fissure-procedures