Anal fissure

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Last reviewed: 25 Apr 2025

Last updated: 22 Dec 2023

Anal fissure 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 and is also seen when wiping.

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.

Definition

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.[1] 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.[2][3][4]

History and exam

Key diagnostic factors

pain on defecation
tearing sensation on passing stool
fresh blood on stool or on paper
anal spasm

Full details

Other diagnostic factors

intermittent symptoms
sentinel pile
fissure visible on retraction of buttock

Full details

Risk factors

hard stool
pregnancy
opiate analgesia

Full details

Diagnostic tests

1st tests to order

clinical diagnosis

Full details

Tests to consider

anal manometry
anal ultrasound

Full details

Treatment algorithm

ACUTE

on presentation

resistant fissures

Contributors

Authors

Nivedh Paluvoi, MD

Assistant Professor of Surgery

Colorectal Surgery

Miller School of Medicine

University of Miami

Coral Gables

Disclosures

NP declares that he has no competing interests.

Acknowledgements

Dr Nivedh Paluvoi would like to gratefully acknowledge Dr John R. T. Monson, Dr John Scholefield, and Dr Jonathan Lund, previous contributors to this topic. JRTM declares that he has no competing interests. JS and JL are authors of a number of references cited in this topic.

Peer reviewers

Stephen H. Leveson, MD, FRCS

Professor

York Hospital

York

Disclosures

SHL declares that he has no competing interests.

Steven Brown, MD, FRCS

Consultant Colorectal Surgeon

Northern General Hospital

Sheffield

Disclosures

SB declares that he has no competing interests.

Jan Rakinic, MD, FACS, FASCRS

Associate Professor of Surgery

Chief

Section of Colorectal Surgery

Southern Illinois University School of Medicine

Springfield

Disclosures

JR is an author of a reference cited in this topic.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Gilani A, Tierney G. Chronic anal fissure in adults. BMJ. 2022 Jan 12;376:e066834.

Lund JN, Nystrom PO, Coremans G, et al. An evidence-based treatment algorithm for anal fissure. Tech Coloproctol. 2006 Oct;10(3):177-80. Abstract

American Gastroenterological Association. American Gastroenterological Association medical position statement: diagnosis and care of patients with anal fissure. Gastroenterology. 2003 Jan;124(1):233-4.Full text

Davids JS, Hawkins AT, Bhama AR, et al. The American Society of Colon and Rectal Surgeons clinical practice guidelines for the management of anal fissures. Dis Colon Rectum. 2023 Feb 1;66(2):190-9.Full text

Menteş BB, Irkörücü O, Akin M, et al. Comparison of botulinum toxin injection and lateral internal sphincterotomy for the treatment of chronic anal fissure. Dis Colon Rectum. 2003 Feb;46(2):232-7. Abstract

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

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Anal fissure

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic tests

1st tests to order

Tests to consider

Treatment algorithm

on presentation

resistant fissures

Contributors

Authors

Nivedh Paluvoi, MD

Disclosures

Acknowledgements

Peer reviewers

Stephen H. Leveson, MD, FRCS

Disclosures

Steven Brown, MD, FRCS

Disclosures

Jan Rakinic, MD, FACS, FASCRS

Disclosures

References

Key articles

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials

Guidelines

Patient information

Log in or subscribe to access all of BMJ Best Practice

Log in or subscribe to access all of BMJ Best Practice

Log in to access all of BMJ Best Practice