Anal pain? It's probably a fissure

Anal pain, anal fissure, anal fissure, botulinum toxinThe anal pain is one of the causes more frequent prompting patients to undergo proctological examination; and the anal fissure Is the most common cause of anal pain.

La anal fissure is a small tear in the skin lining the anal canal. It is a fairly common condition, however, often confused with other conditions that can cause anal pain and bleeding, first and foremost hemorrhoids (although the latter, at least in their early stages, hardly cause pain).

The typical symptoms of anal fissure include anal pain during and/or after defecation and bleeding. Typically, the pain is very intense, resistant to common analgesic therapies, begins with defecation and lasts for hours. It is not uncommon for patients to try to avoid going to the bowels because of the severity of the pain, in this way fueling a vicious cycle that causes worsening symptoms (intense pain -> patient refrains from going to the bowels -> constipation worsens, stools become dehydrated, and fecalomas form -> at the next defecation the pain increases in intensity).

In most cases, the fissure is characterized by increased pressure on the internal anal sphincter. Again, a vicious cycle takes place: anal pain causes further contraction of the sphincter, which in turn causes a decrease in blood flow to the area of the fissure, which prevents it from healing.

La anal fissure normally has a traumatic origin, being caused by anything that cananal pain, anal fissure, anal fissure, botulinum toxin Tear or irritate the skin lining the anal canal. The most typical cause is constipation. They can be acute, chronic, and recurrent; the latter are sometimes associated with a small external nodule called a sentinel polyp.

Diagnosis is made on the basis of clinical history and inspection; normally the fissure is located on the posterior midline of the anal canal, less frequently on the anterior and rarely elsewhere. A key instrumental diagnostic aid is anal manometry, which can distinguish cases with sphincter hypertone from those, much less frequently, in which anal sphincter pressure is normal. 

The treatment of anal fissure

In most cases, simply treating constipation can achieve healing of the fissure. Treatment of acute fissures in almost 90 percent of cases consists of general hygienic measures and local dressings: a diet rich in fruits and vegetables, the intake of high-fiber pharmacological supplements, special stool lubricants such as vaseline oil, and fluids, together with adequate physical activity, help to cure constipation, promote bowel motility, and promote healing of the fissure. Baths in warm water, lasting 10-20 minutes and repeated several times a day after defecation and before bedtime at night, promote relaxation of the anal muscles and contribute to wound healing. Appropriate local therapy, based on nitroglycerin and local anesthetics, causes detente of the anal sphincter and soothes anal pain; this improves the vascularization of the fissure and promotes its healing. Anal dilators also give good results; however, they are not always tolerated by patients.

Botulinum toxin in the treatment of anal fissure

anal fissure, anal fissure, anal pain, botulinum toxinIn recent years, the use of the botulinum toxin injected at the level of the sphincter area led to excellent results.

Botulinum to xin is a proteinaceous neurotoxin produced by a bacterium, Clostridium botulinum. There are seven types of botulinum toxin, labeled with letters A through G. Type A botulinum toxin has been used for decades in cynicism for the treatment of spasms and dystonias, including cervical dystonia or spastic torticollis, blepharospasm, severe primary axillary hyperhidrosis, and strabismus. In aesthetic medicine, botulinum toxin is widely used for the treatment of facial and neck wrinkles.

The use of botulinum toxin in the treatment of anal fissure was first reported in 1993 by W. Jost et al. Since then, studies on the efficacy, both from the point of view of overall cost, outcome, and post-treatment complications compared to local medical therapy with substances such as nitroglycerin that I mentioned earlier and to surgery have multiplied, and have led some Authors to state that the introduction of botulinum toxin in the treatment of anal fissure is comparable to the introduction of laparoscopy in surgery. The main data can be summarized as follows:

  • the efficacy of treatment is dose-dependent and site-dependent (to one side, or both sides, of the fissure, or in the anterior midline, taking into account that the majority of fissures occur in the posterior midline), although, to date, there is no unanimous consensus on the site and dose of injection;
  • sphincterotomy remains the gold standard for the long-term treatment of anal fissure (75.4 percent healing of fissure with botulinum toxin at 12 months versus 94 percent with sphincterotomy); however, sphincterotomy is burdened with a significantly much higher rate of serious complications than botulinum toxin treatment; in a recent study, the use of botulinum toxin in the treatment of anal fissure showed superior efficacy in terms of safety compared with internal anal sphincterotomy;
  • treatment with botulinum toxin is well tolerated, is performed on an outpatient basis, is very effective, and has a very low incidence of complications; it is probably more indicated in elderly patients at greater risk of developing anal incontinence if they undergo sphincterotomy, while surgery remains the best option in young adults with good sphincter tone.

Despite this, and despite the amount of data over time that have demonstrated the efficacy and safety of botulinum toxin in the treatment of anal fissure, this indication is to date off-label, and the treatment is not available in National Health Service hospitals.
The surgical treatment of anal fissure, which is very effective and burdened by a low recurrence rate, consists of internal lateral sphincterotomy, that is, the incision of a small part of the internal sphincter muscle of the anus. It is generally a very welcome procedure for the patient, who sees his anal pain disappear overnight. Most patients go so far as to claim that the same, normal postoperative pain is absolutely negligible compared to the suffering inflicted up to that point by the fissure. Surgery may be followed, in a very small percentage of cases, by modest incontinence to gas and, much more rarely, to feces, which normally disappear as the surgical wound heals. It is quite exceptional that, if the surgery is performed correctly, any incontinence to feces will not regress postoperatively and become chronic.

Recurrent anal fissure

Unfortunately, fissures recur frequently, and usually constipation is always the main cause. Therefore, once the fissure has healed and the pain has disappeared, the effort must be directed toward keeping the stool soft and well lubricated, taking in adequate amounts of fruits, vegetables, and fluids through diet, and, if necessary, continuing to use dietary fiber supplements and Vaseline oil.

What if drug therapy doesn't work?

In these cases, a coloproctologic reevaluation is mandatory. The causes of anal pain are numerous, so the differential diagnostic process is crucial. Among them, in addition to anal fissure, it is worth mentioning:

  • anorectal fistula
  • Coccygodynia (coccyx pain with no apparent cause)
  • thrombosed external hemorrhoids
  • anus elevator syndrome
  • perianal abscess
  • perianal hematoma
  • solitary rectal ulcer syndrome
  • ulcerative colitis
  • anal neoplasms
  • anal sex

Once the absence of these conditions is assured and the presence of the fissure and, on manometry, increased anal sphincter pressure is confirmed, patients with fissures that do not go to healing can be considered for indication for surgical treatment.