-IBIS-1.5.0-
tx
digestive system
anal fistula
diagnoses
definition and etiology
definition:
aka "fistula in ano"; an abnormal passage from the rectum to the outside originating above the internal sphincter; usually from spontaneous or surgical drainage of a pyogenic abscess or occasionally granulomatous disease of the intestine (regional enteritis or TB). Most originate in the anorectal crypts; others may result from diverticulitis, neoplasm, and trauma. In infants, these are congenital and are more common in boys. Rectovaginal fistulae may be congenital or may follow radiation therapy, pelvic surgery, childbirth, or malignancy.
signs and symptoms
signs and symptoms:
history of recurrent abscess followed by discharge
one or more secondary openings visible
in granulomatous disease, the discharge may be watery and the margins of the opening reddened
cordlike tract may be palpated
lab findings:
anoscopy or sigmoidoscopy is often required
course and prognosis
If the fistula is secondary to pregnancy or trauma, the prognosis is good with surgical intervention. The wound heals via granulation with generally good results. If secondary to degeneration of the surrounding tissues, the health of the connective tissue must be addressed before the fistula can satisfactorily resolve.
differential diagnosis
hidradenitis suppurativa
pilonidal sinus
dermal suppurative sinuses
urethroperineal fistulae must be differentiated from cryptogenic fistulae
footnotes