A fistula is an abnormal passage that forms between two internal organs or between the skin and an internal organ. In most cases, fistulas form as a result of developmental abnormalities, injury, or disease. Sometimes, however, a doctor may actually deliberately create a fistula, as in a colostomy, in which a passage is created between part of the colon and the abdominal wall to provide an outlet for feces when a patient's colon has been damaged or destroyed as a result of a condition such as cancer.
Fistulas can form anywhere in the body. One of the most infamous examples of the fistula is an obstetric fistula, a complication of childbirth which can occur in the developing world. In these cases, an opening forms between the vagina and the rectum or between the vagina and the bladder. In the developing world, obstetric fistulas are a serious problem because many women lack access to medical care to have them corrected; organizations such as the Fistula Foundation are working in the developing world to provide women with medical treatment for this debilitating condition.
Another type of fistula is a rectal fistula, often caused by an abscess which bursts. In this case, the rectum drains through to the skin around the anus, instead of through the anus itself. Other examples of fistulas include connections between the trachea and esophagus and fistulas in the digestive tract. People with chronic inflammatory conditions tend to be at increased risk for fistulas because they are more likely to develop abscesses which can create fistulas.
Treatment for a fistula starts with finding the location and determining the path it takes. In some cases, doctors learn that the opening is incomplete or partial, meaning that it is only open on one end. Once the fistula has been pinpointed, a surgical procedure can be performed to close it, with antibiotics to resolve infection. Sometimes, a fistula needs to be kept open during antibiotic treatment to clear infection, and sometimes tubes will be placed so that pus can drain. Once the area is healthy again, a doctor can perform surgery to close the opening.
When such an opening is deliberately created, it is done so with a therapeutic goal in mind, such as creating a temporary route for drainage, or a point of insertion for a feeding tube. The doctor will provide the patient with very specific care instructions so that the patient can manage the opening safely and hygienically.