Causes severe pain on defecation, often described as "like passing broken glass." The pain may continue for 1 to 2 hours and can also be burning in nature.
A small amount of fresh red blood is often passed on the stool.
On examination of the anus, there is often marked spasm of the sphincter muscles, with significant tenderness often precluding digital examination.
Initial treatment should include either topical nitroglycerin or diltiazem, along with a program of supportive care.
Resistant or chronic fissures may benefit from injection with onabotulinumtoxinA, and most cases can be cured by surgical sphincterotomy or anal advancement flap.
Anal fissure is a split in the skin of the distal anal canal characterized by pain on defecation and rectal bleeding. It is a common condition in young to middle-aged adults and may occur in 1 in 350 people in the European Union.  It is the second commonest gastrointestinal complication of pregnancy after hemorrhoids. The pain is described as severe (often described as "like passing broken glass") and has a serious negative effect on quality of life.  
Florida Hospital System
Florida Hospital Medical Group
JRTM declares that he has no competing interests.
Dr John Monson would like to gratefully acknowledge Dr John Scholefield and Dr Jonathan Lund, previous contributors to this monograph. JS and JL are authors of a number of references cited in this monograph.
SHL declares that he has no competing interests.
Consultant Colorectal Surgeon
Northern General Hospital
SB declares that he has no competing interests.
Associate Professor of Surgery
Section of Colorectal Surgery
Southern Illinois University School of Medicine
JR is an author of a reference cited in this monograph.
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