An anal fissure is a tear or crack, in the anus and anal canal. It can be acute or chronic. The initial symptoms include pain during and after bowel movements with bleeding, itching and malodorous discharge. Usually, anal fissures are less than one centimeter across, but the pain due to fissures maybe quite severe as the anus is a very sensitive part of the body and even a small tear can cause pain and discomfort.
An anal fissure can occur due to a number of causes:
Constipation and straining -Constipation and straining during bowel movements and passing hard stools can be the cause of anal fissures.
Persistent Diarrhea -Repetitive diarrhea also can be a cause of an anal fissure.
Pregnancy and childbirth - Pregnant women have a higher risk of getting an anal fissure in their later pregnancy and during childbirth.
Sexually transmitted diseases/Sexually transmitted infections-Syphilis, HIV, HPV, and herpes are the kind of diseases that are associated with a higher risk of having anal fissures.
Anal sex - Very rare but it can cause anal fissures.
Underlying conditions -Some underlying conditions, like Crohn's disease and other inflammatory bowel diseases, may cause anal fissures.
Muscle spasms- There are two muscular rings also known as sphincters control the anus. The outer ring is consciously controlled but the inner ring is not and is under constant pressure. It is believed that, when the pressure increases to a large extent, the inner sphincter might spasm, decreasing the blood flow and increasing the risk of fissures.