An anal fissure is a small split or tear in the thin moist tissue (mucosa) lining the lower rectum (anus).
Overview, Causes, & Risk Factors
Anal fissures are extremely common in young infants but may occur at any age. Studies suggest 80% of infants will have had an anal fissure by the end of the first year. The rate of anal fissures decreases rapidly with age. Fissures are much less common among school-aged children than infants.
In adults, fissures may be caused by constipation, the passing of large, hard stools, or by prolonged diarrhea. In older adults, anal fissures may be caused by decreased blood flow to the area.
Anal fissures are also common in women after childbirth and persons with Crohn’s disease.
Pictures & Images
Anal fissure – series
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.
Reviewed By : Jenifer K. Lehrer, MD, Department of Gastroenterology, Frankford-Torresdale Hospital, Jefferson Health System, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.