Tests and diagnosis

By Mayo Clinic Staff

You can expect a physical exam and certain tests, explained below, depending on your needs.

Physical exam

Your doctor will perform a physical exam to try to locate the rectovaginal fistula and check for a possible tumor mass, infection or abscess. The doctor's exam includes inspecting your vagina, anus and the area between them (perineum) with a gloved hand.

Unless the fistula is very low in the vagina and readily visible, your doctor may use a speculum to see the inside of your vagina. An instrument similar to a speculum, called a proctoscope, may be inserted into your anus and rectum to check for problems. Your doctor may take a sample of tissue for lab analysis (biopsy) during the procedure.

Tests for identifying fistulas

Often a fistula isn't found during the physical exam. Your doctor may recommend other tests, such as those below, to locate and evaluate a rectovaginal fistula. These tests can also help your medical team in planning for surgery.

  • Contrast tests. A vaginogram or a barium enema can help identify a fistula located in the upper rectum. These tests use a contrast material to show either the vagina or the bowel on an X-ray image.
  • Blue dye test. This test involves placing a tampon into your vagina, then injecting blue dye into your rectum. Blue staining on the tampon shows the presence of a fistula.
  • Computerized tomography (CT) scan. A CT scan of your abdomen and pelvis provides more detail than a standard X-ray does. The CT scan can help locate a fistula and determine its cause.
  • Magnetic resonance imaging (MRI). This test creates images of soft tissues in your body. MRI can show the location of a fistula, as well as involvement of pelvic organs or the presence of a tumor.
  • Anorectal ultrasound. This procedure uses sound waves to produce a video image of your anus and rectum. Your doctor inserts a narrow, wand-like instrument into your anus and rectum. Anorectal ultrasound can evaluate the structure of your anal sphincter and may show injury caused during childbirth.
  • Anorectal manometry. This test measures the sensitivity and function of your rectum and can provide useful information about your rectal sphincter and your ability to control stool passage. This test does not locate fistulas, but it can help in planning to repair the fistula.
  • Other tests. If your doctor suspects you have inflammatory bowel disease, he or she may order a colonoscopy to view your colon. During the procedure, your doctor can take small samples of tissue (biopsy) for lab analysis, which can help confirm the diagnosis of Crohn's disease.
Nov. 15, 2012