Rectovaginal fistulas are rare and represent a small portion of all anorectal fistulas. Enterovaginal and vesicovaginal fistulas are the most common types of complications after radiotherapy of larger gynecologic neoplasms and after surgery. Women with colovaginal fistulas may present with feces, flatus, or mucus per the vagina.

Fistulous tract on T2-weighted images or inversion recovery MRI appears as a tract of fluid signal intensity surrounded by lower-signal-intensity granulation tissue and fibrosis. Changes in normal structures in the pelvis are evident on MR images: fascial and muscle edema; thickening of the rectum wall, bladder, and vagina; and fatty infiltration of bone marrow. They depend on the radiation dose and the time elapsed since RT. Increased signal intensity on T2W images usually reflects acute or subacute changes and does not persist indefinitely. Increased signal intensity should not be confused with tumor recurrence.

Fournier gangrene is a necrotizing fasciitis of the perineum. It’s a urologic emergency with a potentially high mortality rate; it is typically seen in diabetic men aged about 50–70.