Fistula is a hole or holes between body cavities, either the vagina and bladder or the rectum and it may be connected to the outside/skin. Fistula usually develops during obstructed labour when the baby's head presses hard on the soft tissues of the mother's pelvic organs, such as the bladder (the organ that holds urine) or rectum (the organ leading stool to the outside). After many hours or even days of pressure, the tissues pressed between the baby's head and the mother's bones die and fall off, leaving a hole. If the bladder is torn, urine leaks uncontrollably through the vagina. If the rectum is torn, faeces passes out through the vagina. In severe cases, both urine and faeces pass uncontrollably.
Attribution: Straight Talk Foundation