An anal fissure is an unnatural crack or tear in the anus, usually extending from the anal opening and located posteriorly in the midline. This location is probably because of the relatively unsupported nature of the rectal wall in that location.

Causes

Most anal fissures are caused by stretching of the anal mucosa beyond its capability. Various causes of this fissure include:

• Straining to defecate, especially if the stool is hard and dry
• Severe and chronic constipation
• Severe and chronic diarrhea
• Crohn's disease and Ulcerative colitis
• Anal sex or dildo use
• Anal stretching
• Insertion of foreign objects into the anus
• Tight sphincter muscles
• Excessive anal probing

Anal fissures are common in women after childbirth and in infants.

Symptoms

The symptoms of anal fissure include:

• Pain during, and even hours after, defecation
• Visible tear in the anus
• Blood in stool or on toilet paper
• Constipation
• Burning, possibly painful, itch

Prevention

In infants under one year old, frequent diaper change can prevent anal fissure. For adults, the following can help prevent fissure:

• Treating constipation by eating food rich in dietary fiber, avoiding caffeine (which can cause dehydration), drinking a lot of water and taking stool softener
• Treating diarrhea promptly
• Lubricating the anal canal with petroleum jelly
• Avoiding straining or prolonged sitting on the toilet
• Using a moist wipe instead of perfumed and harsh toilet paper.
• Keeping the anus dry and hygienic.

Treatment

Most anal fissures are shallow or superficial (less than a quarter of inch or 0.64 cm deep). These fissures self-heal within a couple of weeks. While waiting for the fissure to heal, topical or suppository containing anti-inflammatory agents and local anaesthetic can be used. Furthermore, treatment used for hemorrhoid such as eating a high-fiber diet, using stool softener, taking pain killer and sitz bath can help.

Anal fissures in infants usually self-heal without anything more than frequently changing diapers and treating constipation if the cause.

Painful deep fissures, on the other hand cut through the sphincter muscle thus making it prone to spasm, which exacerbates the fissure and aborts the healing process. Medications such as nitroglycerine and nifedipine ointments can relax the sphincter muscle, thus allowing the healing to proceed. Botulinum toxin injection can also be used to relax the sphincter muscle.

Surgical intervention may be required for persisting deep anal fissures unresponsive to the above conservative measures. Proceedures include:

• Internal lateral sphincterotomy or excising a portion of the sphincter
• Anal dilation or stretching of the anal canal is no longer recommended because of the unacceptably high incidence of fecal incontinence

Despite the high success rate of these surgical procedures (~95%), there are potential side effects, which include: risks from anesthesia, infection, anal leakage or fecal incontinence.

External links

Proctology

Fissure anale