Washington University Colorectal Surgeons answer patient questions regarding anal fissure.
An anal fissure is a cut or tear in the lining of the anal canal. It is associated with severe pain and bright red blood correlated with bowel movements.
Anal fissures can result from trauma due to a hard stool or frequent watery stools. Many times patients will not report an obvious hard or loose stool that causes the fissure. In these cases, it commonly occurs after an episode of pushing and straining to have a bowel movement.
Anal fissure is diagnosed based on a patient’s history and physical exam. Typical symptoms of an anal fissure include sharp stabbing anal pain associated with bowel movements. Experiencing pain, irritation or bright red blood after a bowel movement can also be symptoms of anal fissure. The lingering pain after a bowel movement is a result of spasm of the sphincter and pelvic floor muscles. Pain is typically described as a tearing sensation.
On physical exam, fissures are most commonly located in the anterior or posterior midline. Symptoms can be reproduced by touching with a cotton swab. On visualization, it appears as a cut or ulcer in the anal canal and there may be a small polyp or skin tag associated with it.
The appearance of an anal fissure is dependent upon whether it is acute or chronic. An acute or fresh anal fissure appears as a tear just inside the anus. The longer a fissure is present, the obvious it becomes. The edges become more distinct, and the fissure begins to look like an ulcer. The associated inflammation results in a little polyp like lesion called a sentinel skin tag or anal papilla.
Most fissures will heal spontaneously; however, recurrent fissures, or those with severe symptoms, are unlikely to heal on their own.
Anal fissures typically occur in the posterior or anterior midline locations in the anal canal. Once a fissure occurs, a significant amount of spasm and hypertonicity develop in the internal sphincter muscle. The spastic muscles decrease the blood flow in the area and impair healing, so all therapy is aimed at decreasing the tension in the internal sphincter muscle to ultimately improve the blood flow.
First-line therapy is a high fiber diet with about 25grams of fiber a day and 8 8oz glasses of water a day. One should also avoid pushing and straining. The goal is to have a large bulky stool that allows the anal canal to expand slowly so the muscle stretches in a controlled fashion versus fast when there is straining.
Additionally, a topical ointment such as diltiazem, nifedipine, or nitroglycerin can be prescribed to help relax the internal sphincter muscle. These medicines only temporarily relax the muscle for up to 8 hours so it needs to be applied 2-3 times a day. An improvement in symptoms is expected within 2 weeks of starting this regimen, but it may take up to 16 weeks for symptoms to completely resolve. If symptoms do not improve or persist despite
good compliance with a high fiber diet and a topical ointment, the next step in management is BOTOX injections.
BOTOX will temporarily paralyze the internal sphincter muscle for 3 months. Continuation of the high fiber diet and the topical ointment during this time provides the best results. Because BOTOX paralyzes the internal sphincter muscle, patients may notice alteration in their bowel control. Typically, this is just urgency but may include some anal leakage. The effects of the BOTOX are temporary, so once it has worn off these symptoms should go away.
For patients that have persistent symptoms despite high fiber, topical ointment, and BOTOX, may be a candidate for a sphincterotomy. During this procedure, the internal sphincter muscle is divided. This is the most effective method for healing an anal fissure with a 95% success rate. However, it carries the highest risk with a 1-2% chance of permanent alterations in bowel control. Patients that complain of urgency, anal seepage, or incontinence as baseline are not a candidate for a sphincterotomy.
With good compliance to a high fiber diet and topical therapy, patients should notice an improvement in anal fissure symptoms within 2 weeks; however, it may take up to 16 weeks for complete healing to occur.
The cure rate is typically around 65% after treatment with fiber and a topical agent such as nifedipine, diltiazem or nitroglycerin. Once a fissure is healed, it is not uncommon to have recurrences. Events that can lead to a recurrence of the anal fissure include holidays, vacations, work travel, or an illness. These events may cause a disruption in your typical routine of diet, exercise, and bowel habits.
The effects of BOTOX injections may take up to 5 days for an improvement to be noticed. The addition of BOTOX increases the chances of healing anal fissure to around 75%. Lateral internal sphincterotomy is the most effective treatment for anal fissure with a 95% success rate. Patients should even experience an improvement of symptoms within a few days.
Washington University Colorectal can provide options and treatments for anal fissures. Meet our specialists below.
