High fistula, referred to as rectovaginal fistula, are communications to the rectum, proximal to the anal sphincter. These often involve the posterior vaginal fornix. Low fistula are anovaginal, which are communications from the anal sphincter complex to the lower half of the vagina [34]. Women with rectovaginal or anovaginal fistulae present with stool, gas, or odorous Anorectal Disease mucopurulent discharge from the vagina. These symptoms may be confused for incontinence. Other symptoms include dyspareunia, perineal pain, and recurrent vaginal infections. Rectovesicular fistulae are characterized by the clinical presentation of pneumaturia or fecaluria, which are pathognomonic [1]. Recurrent urinary tract infection may also be a presenting manifestation. Diverticulitis, CD, colorectal or pelvic malignancies, radiation, iatrogenic injury, and postoperative complications are the most common causes. CT Pelvis The appropriate CT protocol for imaging a patient with an anorectal complaint depends upon the presentation and differential diagnosis. IV contrast is preferred to a noncontrast examination to help visualize and characterize fluid collections, abscesses, and fistulous tracts. CT without contrast is not useful in this clinical scenario. CT with and without IV contrast would only be useful when there is benefit from dual-phase imaging, but is not typically performed in this scenario. Water-soluble rectal contrast is generally not necessary to diagnose a rectal abscess and may be challenging to administer, depending on symptom severity. However, rectal contrast may help delineate perforation or leak in a patient with a history of trauma or recent surgery. Water-soluble rectal contrast is preferred over barium to avoid the possibility of barium spilling into the peritoneal cavity or spaces of the extraperitoneal pelvis. Water-soluble rectal contrast is also preferred in a patient who could potentially be undergoing surgery.
Anorectal Disease. High fistula, referred to as rectovaginal fistula, are communications to the rectum, proximal to the anal sphincter. These often involve the posterior vaginal fornix. Low fistula are anovaginal, which are communications from the anal sphincter complex to the lower half of the vagina [34]. Women with rectovaginal or anovaginal fistulae present with stool, gas, or odorous Anorectal Disease mucopurulent discharge from the vagina. These symptoms may be confused for incontinence. Other symptoms include dyspareunia, perineal pain, and recurrent vaginal infections. Rectovesicular fistulae are characterized by the clinical presentation of pneumaturia or fecaluria, which are pathognomonic [1]. Recurrent urinary tract infection may also be a presenting manifestation. Diverticulitis, CD, colorectal or pelvic malignancies, radiation, iatrogenic injury, and postoperative complications are the most common causes. CT Pelvis The appropriate CT protocol for imaging a patient with an anorectal complaint depends upon the presentation and differential diagnosis. IV contrast is preferred to a noncontrast examination to help visualize and characterize fluid collections, abscesses, and fistulous tracts. CT without contrast is not useful in this clinical scenario. CT with and without IV contrast would only be useful when there is benefit from dual-phase imaging, but is not typically performed in this scenario. Water-soluble rectal contrast is generally not necessary to diagnose a rectal abscess and may be challenging to administer, depending on symptom severity. However, rectal contrast may help delineate perforation or leak in a patient with a history of trauma or recent surgery. Water-soluble rectal contrast is preferred over barium to avoid the possibility of barium spilling into the peritoneal cavity or spaces of the extraperitoneal pelvis. Water-soluble rectal contrast is also preferred in a patient who could potentially be undergoing surgery.