| |
| | eMedicine - Anal Fissure : Article Excerpt by: Lisa S Poritz, MD |
 | | Problem: An anal fissure is a painful linear tear or crack in the distal anal canal, which, in the short term, usually involves only the epithelium and, in the long term, involves the full thickness of the anal mucosa (see Images 1-2). |
 | | Studies of the internal anal sphincter and of anal canal physiology have been performed with varied results, but at least one abnormality is likely present in the internal anal sphincter of many anal fissure patients. |
 | | In patients with hypertrophied internal anal sphincters, this delicate blood supply is further compromised, thus rendering the posterior midline of the anal canal relatively ischemic. |
| www.emedicine.com /med/byname/anal-fissure.htm (658 words) |
|