Signs and symptoms of an anal fissure
Idiopathic anal fissures are believed to result from trauma as a consequence of passing a large or hard stool. Whilst physical trauma may be the initiating event, a key characteristic is an increase in anal sphincter pressure (excessive tone). Coupled with a compromised local blood flow, this results in painful defecation and delayed healing.
- Pain, sometimes severe, during bowel movementsPain after bowel movements that can last up to several hours
- Bright red blood on the stool or toilet paper after a bowel movement
- Itching or irritation around the anus
- A visible crack in the skin around the anus
- A small lump or skin tag on the skin near the anal fissure
Causes and risk factors
An anal fissure most often occurs when passing large or hard stools.
Chronic constipation or frequent diarrhoea can also tear the skin around the anus.
Chronic constipation or frequent diarrhoea can also tear the skin around the anus.
Other common causes include:
- straining during childbirth or bowel movements
- inflammatory bowel disease (IBD), such as Crohn’s disease
- decreased blood flow to the anorectal area
- overly tight or spastic anal sphincter muscles
In rare cases, an anal fissure may develop due to:
Treatment
The key target for treatment is relief of pain and facilitation of healing through reduction of anal sphincter pressure.2
The surgical procedure, lateral sphincterotomy, involves division of the internal anal sphincter (IAS). This improves symptoms and promotes healing, but risks causing faecal incontinence (in up to 45% of cases).3
Pharmacological treatments have the advantage of avoiding damage to the IAS. Glyceryl trinitrate (GTN) ointment [Rectogesic / Rectiv], applied locally, relaxes the IAS. It has licensing authorisation for the relief of pain associated with chronic anal fissure. However, it causes headache in up to 57% of patients,4 which can result in poor compliance and treatment failure.
Intra-sphincteric injections of botulinum toxin have been used also. However, this is an invasive and expensive procedure.
Topically applied diltiazem hydrochloride cream also relaxes the IAS. The benefits of diltiazem hydrochloride cream in the treatment of anal fissure (prescribed on a named patient basis), are recognised in a position statement by the influential Association of Coloproctology of Great Britain & Ireland (ACPGBI).2
