The anal canal is a short tube surrounded by muscle at the end of your rectum. The rectum is the bottom section of your colon large intestine. An anal fissure also called fissure-in-ano is a small rip or tear in the lining of the anal canal. Fissures are common, but are often confused with other anal conditions, such as hemorrhoids. Fissures are usually caused by trauma to the inner lining of the anus from a bowel movement or other stretching of the anal canal. This can be due to a hard, dry bowel movement or loose, frequent bowel movements.

An anal fissure can occur when someone passes a large or hard stool poop , which stretches the lining of the anus until it tears. It also can happen when frequent diarrhea irritates the lining. You may also see blood on the stool, baby wipes, or toilet tissue. In infants, anal fissures are very common and tend to heal completely with basic care, including soaks and ointment. In older kids and teens, the cuts can take several weeks or longer to heal and sometimes tear open again.

Hemorrhoids are lumps or masses of tissue in the anus, which contain enlarged blood vessels. Any increase in abdominal pressure may produce hemorrhoids. This may be from:. Internal hemorrhoids.