Diagnosis

You can expect a physical exam and certain tests, 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 inside 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

Your doctor may not find a fistula during the physical exam. Other tests may be needed 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 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 indicates a fistula.
• Computerized tomography (CT) scan. A CT scan of your abdomen and pelvis provides more detail than does a standard X-ray. 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, whether other pelvic organs are involved or whether you have 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. This test can evaluate the structure of your anal sphincter and may show childbirth-related injury.
• Anorectal manometry. This test measures the sensitivity and function of your rectum and can give information about the rectal sphincter and your ability to control stool passage. This test does not locate fistulas, but may help in planning the fistula repair.
• 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 Crohn's disease.