Anal fissure: Clinical sciences

Anal fissures are longitudinal tears in the anal mucosa under the dentate line. Since this region is innervated by somatic nerves, anal fissures are often quite painful.

Now, there are two types of anal fissures: typical or primary fissures, caused by local trauma, and atypical or secondary fissures, which are associated with some other condition, such as Crohn disease.

Alright, the first step when approaching a patient with signs and symptoms suggestive of an anal fissure is to obtain a focused history and physical examination.Patients with typical, or primary, anal fissures usually report severe anal pain that might be present at rest, but worsens during defecation and may persist for several hours.

Additionally, they might report anal bleeding or hematochezia. History might reveal local trauma, such as constipation and passing large, hard stools.

On physical exam, typical anal fissures usually present as superficial lacerations located in the posterior midline. Less commonly, they can be seen in the anterior midline, or in both the anterior and posterior midline.Similarly, individuals with atypical or secondary anal fissures usually report anal bleeding and pain that’s present at rest but worsens during defecation.

History typically reveals chronic, multiple, recurring, and non-healing fissures. On physical examination, you may see multiple wide, deep fissures that are healing poorly.

In contrast to typical fissures, atypical fissures are found in locations other than the midline, often the lateral region.

Additionally, a patient might have perianal skin tags, which are remnants from previous bouts of inflammation. In some cases, perianal skin tags can become edematous and painful.Alright, now that you’ve obtained a history and physical examination, let’s move on to the management of typical anal fissure.

Individuals with typical anal fissures are initially treated with supportive care, which includes stool softeners, sitz baths, and a fiber-rich diet, with or without topical analgesics.

If this initial treatment doesn’t help, you should continue supportive care and add topical calcium channel blockers like nifedipine or topical nitrates.

These can help relax the smooth muscles of the internal anal sphincter and promote healing. Now, most typical anal fissures will heal with this treatment, however if the healing is inadequate and they continue to have symptoms, you should consider that this might be an atypical anal fissure and do a colonoscopy or sigmoidoscopy to look for secondary causes.

If the cause is identified, treat the underlying cause. If not, consider consulting the surgery team for botulinum toxin A injection, lateral internal sphincterotomy, or anal advancement flap Okay, let’s move on to the management of atypical fissures.

Just like with typical anal fissure, start with supportive care. This alone usually won’t be enough, since the underlying secondary cause is not addressed.

So In this case, you should also order a colonoscopy or sigmoidoscopy. Colonoscopy should be done for patients who have risk factors for colon cancer, such as age over 50 and a family history of colon cancer.

All others can undergo a sigmoidoscopy. If you find an underlying cause that can be associated with anal fissures, such as Crohn disease, make sure to treat it.

However, if there is no underlying cause, consult the surgical team for possible interventions. This could involve Injecting botulinum A toxin into the anal sphincter to help relax the tense, hypertonic anal sphincter muscle and, in turn, improve healing in chronic fissures.

On the other hand, a lateral internal sphincterotomy involves cutting internal anal sphincter muscle fibers up to the apex of the fissure or the dentate line.

This reduces the pressure created by the internal sphincter, increases blood flow, and promotes healing. Lastly, an anal advancement flap is an alternative to a lateral internal sphincterotomy in patients who are at risk of developing fecal incontinence.

During this procedure, a skin flap is created from the skin around the anus and used to cover the fissure.Alright, as a quick recap… Anal fissures are a common cause of bleeding and severe anal pain and bleeding.

Individuals with typical or primary anal fissures can typically be treated with supportive care such as stool softeners, sitz baths, a fiber-rich diet, topical analgesics, and possibly topical calcium channel blockers or topical nitrates.

If there’s no improvement, order a colonoscopy or sigmoidoscopy to identify an underlying cause, such as Crohn disease. If no cause is identified, you should consult surgery.

For atypical, or secondary anal fissure, also start with supportive care but also do a colonoscopy or sigmoidoscopy right away to identify the cause.

If the cause is identified, treat the cause. If not, obtain a surgical consultation for a botulinum toxin A injection, lateral internal sphincterotomy, or anal advancement flap.