Perianal Abscess
Perianal abscess is a collection of pus around the anal region that results from infection of the glands in the anal canal.
Patient usually experience pain and discomfort around the anal region. It is often associated with an area of swelling around the anus and can be associated with fever.
Treatment is surgical drainage, often done under general anaesthetics.
Approximately 50% of patients with perianal abscess will develop perianal fistula.
Anal Fistula
Anal fistula is an abnormal connection between the anal canal and the skin around the anus.
It often develops after drainage of perianal abscess but may occur spontaneously. Symptoms include intermittent or continuous discharge of mucus, pus or blood from the external opening. Episodic infection and abscess formation may occur.
Symptomatic fistulas will require surgical treatment. Most fistulas are simple but it can be complex with multiple tracks. Complex fistula usually require further investigations to assess the extent of the fistula. Investigations may include CT scan, MRI, transanal US and examination under anaesthesia.
Depending on the extent and location of the fistula, and the status of anal sphincters, various treatment options are available. Aims of surgical treatment are elimination of the fistula tract with low recurrence rate while maintaining sphincter function and minimising incontinence. Surgical treatments includes fistulotomy, insertion of seton, mucosal advancement flap and LIFT procedure.
Anal Fissure
Anal fissure is a split or a tear in the lining of the anal canal. It is a result of trauma to the anal canal, usually the passage of hard stool. It causes pain and spasm of the muscles of the anal canal which results in reduced blood supply to the lining of the anal canal, ultimately resulting in the non-healing of the tear.
Patients most readily reports pain, especially when passing stool. Sometimes, rectal bleeding can occur. This usually results in reluctance to go to toilet and constipation often occurs, adding further trauma to the anal canal. Chronic inflammation associated with anal fissure may result in formation of skin tags.
Aim of treatment is to break the cycle of pain and spasm so healing can occur. First line treatment should be conservative which includes high fibre diet, plenty of water and pain relief. Important to keep stool soft and stool softener may be required. To help the anal sphincter muscles to relax, topical application of ointments are usually prescribed. It is important to allow at least 6 weeks for the treatment to work.
Small percentage of patients will have persistent fissure despite best conservative treatment. Surgical interventions include lateral sphincterotomy or injection of botulinum toxin (Botox).