Anal fissures are tears in the skin overlying the anal sphincter, usually due to increased tone of the anal sphincter muscles, and a failure of these muscle to relax. Anal fissures cause pain during defecation and bleeding from the anus.
Review Date 5/17/2020
Updated by: Debra G. Wechter, MD, FACS, general surgery practice specializing in breast cancer, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.