Anal fissure

Fissure in ano; Anorectal fissure; Anal ulcer

An anal fissure is a small split or tear in the thin moist tissue (mucosa) lining the lower rectum (anus).

Rectum

The rectum is the final portion of the large intestine. It empties stool from the body through the anus.

Normal anatomy

The anus is a sphincter at the end of the rectum through which passes stool during defecation. The anal sphincter is a critical mechanism for control of fecal continence.

Causes

Symptoms

Exams and Tests

Treatment

Outlook (Prognosis)