An anal fissure is a tear, cut or ulceration of the special skin at the opening of the anus, which causes pain, bleeding, itching or burning. A fissure can be caused by passing a hard bowel movement, or by diarrhea or inflammation. Fissures often persist and may require helpful measures to heal.

A fissure is usually associated with high pressures of the internal anal sphincter, the innermost muscle of a group of muscles that surround the anal opening and control the passage of gas and stool. Most patients with anal fissure have evidence of an overactive internal anal sphincter. Measures to relax this muscle are often effective in healing fissures.

Self-care

The initial recommendations to help a fissure heal are usually non-operative. These include a high fiber diet, fiber supplements, emollient creams or ointments, lubricating suppositories and sitz baths. If the fissure was caused by hard stools, treatment should include stool softeners, increased water intake and exercise. Most fissures will heal with these measures.

Topical Medicated Agents

Special medicated creams or ointments, nitroglycerin, diltiazem and nifedipine, can relax the internal anal sphincter, relieve pain and burning, and help fissures heal. RECTIV®, a commercial nitroglycerin ointment, is available by prescription. Nitroglycerin preparations tend to produce more headaches, so colorectal surgeons often prefer nifedipine or diltiazem ointment, with or without a topical local anesthetic mixed in, compounded at a local pharmacy.

BOTOX®

Injection of BOTOX® directly into the internal anal sphincter can also be an effective treatment. BOTOX® (Botulinum Toxin Type A) is a purified neurotoxin that produces a temporary localized muscle paralysis. It can be administered in the office without anesthesia.

Surgical Interventions

Lateral Internal Sphincterotomy – When fissures fail to heal with non-surgical management, or when the fissure is chronic, recurrent or extremely painful, surgical intervention is warranted. Most colorectal surgeons perform “lateral internal sphincterotomy” when they believe the sphincter pressure is high. This operation can be performed with a small incision (“open”), or through a smaller puncture (“subcutaneous lateral internal sphincterotomy”). Lateral internal sphincterotomy has a high success rate, 90 to 95%; but infrequently has complications, such as bleeding, abscess and fistula. There can be delayed or non-healing of the sphincterotomy surgical site, and persistence or recurrence of the fissure. This operation, in which anal muscle fibers are cut, has a low but significant chance of causing mild incontinence (loss of control). Reported rates of incontinence after sphincterotomy vary greatly. This is partly because of discrepancies between what patients who had sphincterotomy tell their surgeon and what they report in questionnaires completed in a more private setting. What surgeons tell their patients about this operation also varies greatly. Some surgeons tell their patients they have never seen incontinence in any of their own patients. Others quote minor incontinence rates up to 30%; most quote rates in between. Researchers from the Cleveland Clinic warned that patients undergoing lateral internal sphincterotomy need to be informed about the potential risks for incontinence to flatus (gas), which may occur in up to 30 percent of cases and could be permanent. There have been a number of malpractice cases against surgeons resulting from complications related to sphincterotomy.

Standardized Anal Dilatation – Anal dilatation (sphincter stretch) is another way to treat anal fissure. An older method of anal dilatation was commonly used until lateral internal sphincterotomy was introduced in 1969. In this older method the surgeon inserted his fingers into the anus to spread the anal opening “manually.” This method was relatively uncontrolled, and occasionally resulted in some degree of incontinence. In the 1970’s lateral internal sphincterotomy became the preferred operation for anal fissure because studies showed it produced lower rates of incontinence than “manual dilatation.”

In the 1990’s Dr. Norman Sohn developed a procedure that stretches the sphincter muscle in a measured and controlled way, that is less likely to produce incontinence than “manual dilatation” or lateral internal sphincterotomy. This procedure also avoids other postoperative complications, such as sphincterotomy site bleeding, abscess and fistula. Dr. Sohn and his partner Dr. Michael Weinstein treated more than 2000 fissures this way with excellent results. Dr. Sohn claimed to have an 87% fissure healing rate (95% pain relief with or without full healing) and a minor incontinence rate of 0.3%, although he did not publish these results. He preferred using special dilators and a simple, standardized method. Few surgeons have adopted “Standardized Anal Dilatation” due to a lack of awareness and training, and the negative reputation of “manual dilatation.” A study from Israel published in April, 2021 found that Standardized Anal Dilatation using Sohn’s Dilators is a simple, reliable, consistent, less traumatic, reproducible, and non-operator-dependent treatment for anal fissure, and that its beneficial effects are comparable to sphincterotomy, but it minimizes complications and does no long-term harm to anal sphincter function. There are other scientific studies that support the value of controlled anal dilatation, but there is a need for more studies to compare Standardized Anal Dilatation to lateral internal sphincterotomy. Some believe that Standardized Anal Dilatation should be included in the armamentarium of all colon and rectal surgeons and presented as an alternative to sphincterotomy whenever informed consent is obtained for surgical management of anal fissure.

Fissurectomy – Lateral internal sphincterotomy and Standardized Anal Dilatation can both be performed with or without fissurectomy. Fissurectomy removes deformed skin around the fissure along with protrusions (e.g., sentinel piles or hypertrophied papillae) associated with the fissure, and/or cauterizes the fissure. When a subcutaneous tract (or pocket) has formed beneath anoderm distal or proximal to a fissure, unroofing the tract (“subcutaneous fissurotomy”), may be helpful. 

Other surgical approaches exist to cure anal fissure. Combining BOTOX® injection with Standardized Anal Dilatation and/or fissurectomy is effective. Operations that do not weaken the anal sphincter and are particularly useful when it is suspected or proven that the patient’s anal sphincter pressures are not elevated, or are low, or if they have loose bowel movements, urgency, or already have problems with control. Fissurectomy alone can be performed. Adjacent skin (dermal flap) can be moved into the anus to cover the fissure. Adjacent skin and fat can also be moved to cover the fissure (e.g., V-Y anoplasty). These tissue transfer operations take longer to do, but there are reports showing them to have high success rates.

A Variety of Options

Anal fissure is a common anorectal problem, yet there are a variety of management options. The patient and doctor should consider all options, and choose those best for the individual patient. As in all surgical endeavors, the surgeon should be guided by the principle “primum non nocere”-first, do no harm.