Medically, a fistula is an abnormal connection (hole or tube) between two organs in the human body that aren't normally connected. A fistula can occur almost anywhere in the body. Many disorders and abnormalities can cause fistula, but usually they come about from injury, or less commonly from inflammation or infection.

Obstetric fistula is a particularly worrisome and common type of fistula in the developing world. It happens to women during particularly awkward childbirth. A prolonged labour with the fetus stuck in the birth canal can cause blood supplies to be cut off in the perineum area. Tissue here litterally dies off and rots, encouraged by any subsequent tearing of the vagina when the fetus finally exits the vagina. The woman ends up with a hole between the vagina and the anus.

Even with very good medical care this would be a serious injury with potential lifelong effects. However, in the developing world it can be devastating. Without medical treatment the fistula is unlikely to close up. The woman affected becomes socially ostracised and ashamed of her condition.

Several worldwide campaigns are running to improve obstetric care and try to lower the risk of fistulas occurring.