The amount of bleeding is typically small. Frequently, hemorrhoids develop because of straining during bowel movements, especially if the person has constipation. An anal fissure is a tear in the lining of the anus that is usually caused by a hard bowel movement. Fissures are painful and bleed when the tissue is stressed during bowel movements. Anorectal abscesses are characterized by pus-forming infections in the anorectal region.
Painful abscesses form under the skin.
An anorectal fistula is an abnormal opening or channel from the anorectal area to another part of the body. Typically, the channel leads to pockets of skin near the anus. When seen in infants, anorectal fistulas are considered birth defects. These are seen more frequently in boys than in girls. Fistulas are also seen more frequently in people who have other diseases, including Crohn's disease, tuberculosis, cancer, and diverticulitis.