A fistulectomy is a surgical procedure used to treat a fistula. A fistula is an abnormal connection or tunnel that forms between two organs or between an organ and the skin. For example, an anal fistula is a common type that forms between the inside of the anus and the skin near the anus. This can cause pain, infection, and other complications. A fistulectomy involves removing the entire fistula tract to prevent further problems.