MONTHLY ARTICLE

ANAL FISSURE
One of the most common disorders that we see is anal fissure. An anal fissure is a "cut" or "ulcer" that usually occurs in either the front or the back of the anus. It is usually the result of a transient bout of constipation or diarrhea. Almost everyone will get a fissure at some point in their life, but they usually go away spontaneously as soon as the transient bout of constipation or diarrhea resolves and things return to normal. There are other conditions that may cause an anal fissure, but they are somewhat rare and will not be discussed here.

Symptoms of anal fissure usually consist of painful defecation, post-defecatory pain and sparse bleeding. Most patients will attribute the problem to their hemorrhoids. However, an examination will quickly identify the diagnosis. At this point, the fissure is termed an acute anal fissure and most fissures (i.e. nine out of ten) will heal uneventfully at this stage. The usual regimen of treatment is to place the patient on psyllium, stool softeners and lubricate the canal with suppositories along with adjutant warm tub soaks. This regimen will heal most acute and some more chronic fissures. I usually allow about four weeks for the regimen to work. If the fissure remains unhealed at four weeks, despite the patient’s compliance with the above regimen, then several options remain:

The fissure is showing some signs of healing and/or is not causing any further pain- in these cases, I will continue the regimen for additional weeks and see if the fissure will heal.

Nitroglycerin ointment- the use of nitroglycerin ointment has been receiving a fair amount of attention in the literature because of its ability to relax the anal sphincter muscle and get a percentage of "more difficult" anal fissures to heal or aid the healing of acute anal fissures. The main potential side-effect is headache. The literature is divided about the true efficacy of nitroglycerin ointment for anal fissure. There is one contingent that feels it will heal additional fissures that otherwise would remain unhealed and require surgery and there is another contingent that feels that nitroglycerin ointment is an aid to the healing of fissures that would normally go on and heal anyway, but will not decrease the number of anal fissures requiring surgery. Personally, I agree with the latter statement as in my experience, most acute fissures will heal under the basic treatment as I have outlined above and most of the more chronic fissures will require surgery.

Surgery- the surgical treatment of choice for anal fissure is lateral sphincterotomy. This surgery is performed in an outpatient setting and usually under general anesthesia. Both the procedure and the post-op recovery period are short. The potential side-effect of a sphincterotomy is anal incontinence. The actual occurrence of this complication is rare, the possibility is there. The surgery involves the cutting of the internal anal sphincter muscle through a tiny perianal incision made on the lateral side (usually the left). The physiology behind this surgery is that there are two anal sphincters, an external voluntary sphincter (your main control muscle) and an involuntary internal sphincter. When a bowel movement enters and distends the rectum, tiny nerves send impulses to the involuntary internal sphincter and tell it to relax. This allows the bowel movement to come down to the "sensation area" of the rectum so that the person can tell whether they are dealing with stool or gas and then can decide to either pass it or hold it by using their external voluntary anal sphincter. If they decide to go, then the bowel movement passes. As it does, it hits the "anal fissure or ulcer" (the base of which is the internal anal sphincter) causing it to spasm. This is the pain with defecation that accompanies an anal fissure. This contraction puts additional pressure forces on both the front and the back of the anus and causes recurrent propagation and retardation of healing of the existing anal fissure. This process causes recurrent scarring in the area of the existing fissure and it becomes chronic. By placing a lateral cut in the internal sphincter, pressure is taken of the front and back of the anus and the fissure heals. The quoted rate of healing is 95%, but in my experience, the percentage of healing approaches 100%