An anal fissure results from a tear in the lining of the anus and is a common affliction of the anus. Each bowel movement produces pain and bleeding due to irritation of the open cut and also prevents the cut from healing, resulting in the fissure. The fissure can be likened to a persistent paper cut of the anus.
Causes
Constipation causes most anal fissures, especially in patients with increased anal sphincter tone and thus a smaller anal opening. A hard stool forced through the narrower orifice tears the anal lining. The fact that this occurs repeatedly with each bowel movement means that the tear does not have time to heal, leading to a fissure.
Diarrhea also predisposes patients to anal fissures, because increased use of the anus traumatizes its lining, causing it to tear and fissure. Other less-common causes of anal fissures include lymphoma, leukemia, Crohn's disease and radiation.
Symptoms
Pain and bleeding are the leading symptoms of anal fissures. Pain results from the repeated trauma to the open fissure. Patients often describe the pain as having a sharp, ripping quality and as occurring only with bowel movements. However, the pain can last up to several hours afterward.
Bleeding with a fissure is generally mild. Patients report blood-streaked bowel movements or blood-stained toilet paper. Rarely does a fissure bleed heavily.
Non-Surgical Treatment
Initial treatment of anal fissures incorporates methods to sooth pain and relieve constipation. Warm baths, fiber and mild steroid suppositories effectively treat 50 percent of fissures.
More difficult cases can be treated with medicated prescription creams that relax the anal sphincter enough to allow easier passage of stool but not enough to cause incontinence. This reduces trauma from repeated bowel movements and gives the fissure a chance to heal. The creams may contain the medications nitroglycerin, nifedipine or diltiazem. Botox injections in the anal sphincter also achieve the same effect and are sometimes used in patients who do not respond to other medications.
Surgical Treatment
Surgery for anal fissures relaxes the sphincter, much as the medicated creams and Botox do. However, it achieves this mechanically rather than chemically through a procedure called a partial sphincterotomy. The surgeon makes a small incision in the anal sphincter, enough to loosen it but not enough to compromise bowel control. The procedure takes very little time and is done on an outpatient basis.
Other surgical procedures include anal dilatation and advancement flaps. The former is almost never performed due to a high incontinence rate. The latter is reserved for complicated cases.
Prevention
Eating a high-fiber diet and staying well-hydrated to prevent constipation will help prevent anal fissures. Exercise and stress management will also help avoid constipation.
