An anal fissure is a minute or thin tear in the mucosal lining of the anus or anal canal. The anus is the opening through which your digestive system releases waste discharge in the form of stool. Persistent strain or pressure around the anus lining can result in an anal fissure. It is much more common among infants, and the risk of this condition decreases with increasing age. Dietary factors, bowel movement habits, and certain lifestyle factors can contribute to the development of this condition.
Long-term constipation is one of the most common causes of anal fissure. Constipation results in the formation of hard, dry stools that are difficult to pass. Often, excessive straining is required to pass stool which can tear the anal mucosa. Chronic diarrhea can also cause anal fissures. Another cause that has become more common is anal sex. Inserting foreign objects into the anal canal can also stretch the muscle layer beyond its limits, thus resulting in a tear.
In certain cases, underlying medical conditions can also lead to the formation of anal fissures. These diseases include Crohn’s disease, ulcerative colitis, leukemia, and anal cancer. Sexually transmitted infections such as syphilis, chlamydia, HIV, etc., are also responsible. Scarring in the anal regions due to previous surgery or disease can also make it more prone to tear with straining. An anal fissure may also occur after normal childbirth in some cases.
Anal fissures can develop at any age, although it is more common among infants. In adults, the risk of developing anal fissures depends on their lifestyle, dietary habits, and bowel movements. People who have a sedentary lifestyle, eat less fiber, drink less water, or have irregular bowel movements are more likely to develop anal fissures due to constipation. Anal sex or insertion of foreign objects can also be a risk factor. If you have an underlying medical condition associated with your digestive tract, it may increase the risk of developing anal fissures.
Pain is the most common symptom associated with anal fissure. It can range from mild to severe, depending on the size and extent of the anal fissure. Pain is often felt during defecation, especially if you are straining hard to pass stool. This pain and discomfort can also last for several hours after a bowel movement. Anal fissures may also bleed while you are passing stool. If bleeding occurs, you can notice bright red blood in your stool or on the toilet paper. You may also experience a burning or itching feeling in your anus region. This discomfort may also be felt during urination. If it is large enough in size, it can be seen as a crack in the anus or anal canal that may or may not be connected with a skin tag.
In majority of the cases, the diagnosis of anal fissure is made on the basis of history and clinical presentation alone. Your doctor will ask about your dietary habits and other factors that may have caused this condition. Upon visual inspection, an anal fissure is visible as a thin crack in the front, back, or sides of the anus. If your doctor suspects an underlying condition contributes to the formation of an anal fissure, they may recommend further tests to confirm the diagnosis. These tests may include anoscopy, flexible sigmoidoscopy, or colonoscopy. These tests are more invasive and are only done if an underlying disease is suspected.
Anal fissure needs to be differentiated from other diseases that can cause pain and difficulty passing stool. These conditions can include hemorrhoids, anal fistula, perianal abscess, rectal prolapse, and anal cancer. Differentiation can be done on the basis of history, symptoms, physical examination, and diagnostic tests.
Anal fissures usually heal themselves if they are small in size. The initial treatment measures focus on making the stool soft for easy removal through the anus. This can be achieved by increasing fiber content in your diet and drinking more water. Soaking the affected region in warm water for about 10 to 15 minutes can promote healing and relax your anal sphincter muscles. Cleansing the anorectal area with water and applying petroleum jelly afterward can also help keep the site lubricated.
If these techniques don’t work, your doctor may recommend suitable medications to improve this condition. If your condition still does not respond to any treatment, surgery is the last option. Lateral internal sphincterotomy (LIS) is done in which a small portion of your anal sphincter muscle is removed. This does not affect your bowel movements in the future.
Topical hydrocortisone creams or foams can be used upon prescription. Topical anesthetics such as lignocaine can also be used to relieve pain. In certain cases, external nitroglycerin is applied to increase blood flow and promote healing. Other medications may include botulinum toxin, nifedipine, and diltiazem.
About 80% to 90% of the cases heal with improvement in lifestyle factors and dietary habits. Medication or surgery is only required in severe or chronic cases of anal fissures.
In infants, anal fissures can be prevented by treating the possible causes of constipation and changing diapers frequently. In adults, maintaining a diet rich in fiber and drinking more water can help avoid constipation. Keep the anorectal area dry and use soft toilet paper or cotton pads to clean the area. Avoid sitting on the toilet for too long or engaging in activities that stretch your anorectal muscles for a long duration.
Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on April 27, 2023.