What is an anal fissure?
An anal fissure is a tear in the lining of the anus or anal canal (the opening through which stool passes out of the body). The fissure can be painful and may bleed.
What are the signs and symptoms of an anal fissure?
Signs and symptoms include:
- Pain during, and even hours after -- a bowel movement
- Blood on the outside surface of the stool
- Blood on toilet tissue or wipes
- A visible crack or tear in the anus or anal canal
- Burning and itch that may be painful
- Discomfort when urinating, frequent urination, or inability to urinate
- Foul-smelling discharge
What causes an anal fissure?
Anal fissures can be caused by trauma to the anus and anal canal. The cause of the trauma can be one or more of the following:
- Chronic constipation
- Straining to have a bowel movement, especially if the stool is large, hard, and/or dry
- Prolonged diarrhea
- Anal sex, anal stretching
- Insertion of foreign objects into the anus
Causes other than trauma include:
- Longstanding poor bowel habits
- Overly tight or spastic anal sphincter muscles (muscles that control the closing of the anus)
- Scarring in the anorectal area
- Presence of an underlying medical problem: such as Crohn's disease and ulcerative colitis [types of inflammatory bowel disease]; anal cancer; leukemia; infectious diseases (such as tuberculosis); and sexually transmitted diseases (such as syphilis, gonorrhea, Chlamydia, chancroid, HIV)
- Decreased blood flow to the anorectal area
Anal fissures are also common in women after childbirth and in young infants.