History

Patients often provide a reliable history of previous pain, swelling, and spontaneous or planned surgical drainage of an anorectal abscess. Signs and symptoms of fistula-in-ano, in order of prevalence, include the following:

Perianal discharge
Pain
Swelling
Bleeding
Diarrhea
Skin excoriation
External opening

Important points in the patient’s history that may suggest a complex fistula include the following:

Inflammatory bowel disease
Diverticulitis
Previous radiation therapy for prostate or rectal cancer
Tuberculosis
Steroid therapy
HIV infection

A review of symptoms may reveal the following in patients with a fistula-in-ano:

Abdominal pain
Weight loss
Change in bowel habits

Physical Examination

Physical findings are the mainstay of diagnosis.

The examiner should observe the entire perineum, looking for an external opening that appears as an open sinus or elevation of granulation tissue. Spontaneous discharge of pus or blood via the external opening may be apparent or expressible on digital rectal examination.

Digital rectal examination (DRE) may reveal a fibrous tract or cord beneath the skin. It also helps to delineate any further acute inflammation that is not yet drained. Lateral or posterior induration suggests deep postanal or ischiorectal extension.

The examiner should determine the relationship between the anorectal ring and the position of the tract before the patient is relaxed by anesthesia. The sphincter tone and voluntary squeeze pressures should be assessed before any surgical intervention to determine whether preoperative manometry is indicated. Anoscopy is usually required to identify the internal opening. Proctoscopy is also indicated in the presence of rectal disease (eg, Crohn disease or other associated conditions). Most patients cannot tolerate even gentle probing of the fistula tract in the office, and this should be avoided.

Workup

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Media Gallery

Anatomy of the anal canal and perianal space.
Fistula-in-ano. Goodsall rule.
Parks classification of fistula-in-ano.
Schematic of intersphincteric and low transsphincteric fistulotomy.
Schematic of high transsphincteric fistulotomy with seton.

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Author

Juan L Poggio, MD, MS, FACS, FASCRS Professor of Surgery, Department of Surgery, Lewis Katz School of Medicine at Temple University; Colon and Rectal Surgeon, Department of Surgery, Cancer Treatment Centers of America; Colon and Rectal Surgeon and General Surgeon, Division of Colon and Rectal Surgery, Department of Surgery, Temple University Hospital and Jeanes Hospital

Juan L Poggio, MD, MS, FACS, FASCRS is a member of the following medical societies: American College of Surgeons, American Society of Colon and Rectal Surgeons, Association for Academic Surgery, Pennsylvania Society of Colon and Rectal Surgeons

Disclosure: Nothing to disclose.

Chief Editor

John Geibel, MD, MSc, DSc, AGAF Vice Chair and Professor, Department of Surgery, Section of Gastrointestinal Medicine, Professor, Department of Cellular and Molecular Physiology, Yale University School of Medicine; Director of Surgical Research, Department of Surgery, Yale-New Haven Hospital; American Gastroenterological Association Fellow; Fellow of the Royal Society of Medicine

John Geibel, MD, MSc, DSc, AGAF is a member of the following medical societies: American Gastroenterological Association, American Physiological Society, American Society of Nephrology, Association for Academic Surgery, International Society of Nephrology, New York Academy of Sciences, Society for Surgery of the Alimentary Tract

Disclosure: Nothing to disclose.

Acknowledgements

Oscar Joe Hines, MD Assistant Professor, Department of Surgery, University of California at Los Angeles School of Medicine

Oscar Joe Hines, MD is a member of the following medical societies: Alpha Omega Alpha, American Association of Endocrine Surgeons, American College of Surgeons, Association for Academic Surgery, Society for Surgery of the Alimentary Tract, and Society of American Gastrointestinal and Endoscopic Surgeons

Disclosure: Nothing to disclose.

David L Morris, MD, PhD, FRACS Professor, Department of Surgery, St George Hospital, University of New South Wales, Australia

David L Morris, MD, PhD, FRACS is a member of the following medical societies: British Society of Gastroenterology

Disclosure: RFA Medical None Director; MRC Biotec None Director

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

Dennis F Zagrodnik II, MD, FACS Consulting Staff, Premier Surgical of Wisconsin, SC

Dennis F Zagrodnik II, MD, FACS is a member of the following medical societies: American College of Chest Physicians, American College of Surgeons, American Medical Association, Phi Beta Kappa, Society of American Gastrointestinal and Endoscopic Surgeons, Southeastern Surgical Congress, and Wisconsin Medical Society

Disclosure: Nothing to disclose.

Fistula-in-Ano Clinical Presentation

History

Physical Examination

References

Tables

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