Anal fissures are small tears in the epithelium of the anus that can be intensely painful. Most anal fissures are caused due to straining during bowel movements, constipation or repeated diarrhoea.
Who are at risk:
- Women giving birth are at increased risk of developing anal fissures due to pressure on the perineum.
- Spasm of the anal sphincter or local ischaemia can predispose people to, or worsen, anal fissures.
- Atypical anal fissures may develop in people with Crohn’s disease, sexually transmitted diseases (particularly HIV, syphilis and herpes simplex), anal cancer, local trauma (anal intercourse), tuberculosis or receiving chemotherapy
- Intense pain during defecation that often persists for one to two hours
- Presence of blood on the toilet paper, and
- Tearing sensation during bowel movements
Complications: may arise if left untreated.
- failure to heal/chronic fissure
- anorectal fistula
- abscesses may develop
- faecal impaction can occur due to intense and intolerable pain during defecation
Initial management is directed at minimising further local trauma, providing adequate pain relief, relaxing the anal sphincter spasm and avoiding further constipation.
- Laxatives and fibre supplements: Stool must be kept soft (the passage of hard stool may undo weeks or months of healing)
- Pain relief measures:
- Sitz bath: regular warm salted baths
- local anaesthetic creams and
- oral pain medications (analgesics)
Surgical techniques are commonly used for anal fissures which are resistant to medical therapy. They are aimed to relax the internal sphincter. They include:
- open lateral sphincterotomy,
- closed lateral sphincterotomy and
- posterior midline sphincterotomy.
Surgery is consistently superior to medical management options, although it should only be considered in people with chronic, non-healing anal fissures where medical treatments have failed. There is a slight risk of flatus and faecal incontinence following surgery.