Concepts in Surgery of the Anus, Rectum, and Pilonidal Region

  • Amanda M. Metcalf


Successful management of anorectal disease depends on a clear understanding of what symptoms can be attributed to various conditions.1,2 In addition, consideration must be given to the impact of other aspects of colorectal physiology on function and healing. The perianal skin and lower aspect of the anal canal is richly innervated by sensory fibers. External hemorrhoids are venous plexuses located below the dentate line and covered with squamous epithelium. Internal hemorrhoids are submucosal vascular tissue containing blood vessels, smooth muscle, and connective tissue that are normally located above the dentate line. They are covered with transitional epithelium. Chronic straining is thought to cause excessive engorgement of the vascular cushions and disruption of the smooth muscle and connective tissue. This disruption allows the vascular cushions and the overlying muscosa to slide down the anal canal and prolapse during straining. Repetitive straining promotes further prolapse.


Irritable Bowel Syndrome Anal Canal Dentate Line External Sphincter Hidradenitis Suppurativa 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Beck DE, Wexner SD. Fundamentals of Anorectal Surgery, 2nd ed. Philadelphia, Saunders, 1998.Google Scholar
  2. Gordan PH, Nivatvongs S. Principles and Practice of Surgery for Colon, Rectum and Anus, 2nd ed. St. Louis, Quality, 1999.Google Scholar
  3. Parks AG, Hardcastle JD, Gordon PH. A classification of fistula-in-ano. Br J Surg 1976;63:1.CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2006

Authors and Affiliations

  • Amanda M. Metcalf
    • 1
  1. 1.Department of SurgeryUniversity of Iowa Carver College of MedicineIowa CityUSA

Personalised recommendations