The anatomical anal canal extends from the perineal skin to the linea dentata. Surgically, the anal canal extends from the perineal skin to the anorectal ring. This is the circular upper border of the puborectal muscle which is digitally palpable upon rectal examination. The anorectal ring lies approximately ,5 cm above the linea dentata.

Perianal Fistulas



Anal fistula - NHS
Mayo Clinic doctors trained in colon and rectal surgery, gastroenterology, and infectious disease, as well as wound care experts, work together to evaluate and treat people with anal fistula. If you have Crohn's disease or another medical condition, Mayo Clinic specialists will collaborate with your primary care doctor to form the best treatment plan. Having all this expertise in a single place means that your care is discussed among the team, test results are available quickly, appointments are scheduled in coordination and the most highly specialized experts in the world are all working together for your health. Knowing the complete path of an anal fistula is important for effective treatment. The opening of the channel at the skin external generally appears as a red, inflamed area that may ooze pus and blood.


Perianal Fistulas in Dogs
Get the PDF version of this article. Anorectal abscesses are fairly common and are a source of considerable morbidity. Beginning as perianal or perirectal cellulitis originating from an anal gland infection, the inflammatory process grows and spreads to the soft tissues around the anorectum.



Anal fistula is a chronic abnormal communication between the epithelialised surface of the anal canal and usually the perianal skin. They can form when anal abscesses do not heal properly. Anal fistulae originate from the anal glands , which are located between the internal and external anal sphincter and drain into the anal canal. The tract formed by this process is a fistula. Abscesses can recur if the fistula seals over, allowing the accumulation of pus.