A fistula is an abnormal connection between two organs or vessels that normally do not connect to each other. Fistulas are the result of injuries, surgeries, inflammation, or infections. They can be of different types such as anal fistula, urinary fistula, and gastrointestinal fistula. Fistula treatment is usually done through medications including antibiotics, surgery, or both. Fistula removal may become necessary if the infection becomes too severe or doesn't respond well to medications.