Abstract
An appendico-sigmoid fistula is a rare entity that has seldom been reported in the literature. In review articles, there are only several reports of appendiceal fistulas, including two into the ileum, two into the ascending colon, two into the sigmoid colon, and one into the Meckel's diverticulum. Presumably, these cases were caused primarily by antecedent appendicitis and diverticulitis. We experienced a case of an appendico-sigmoid fistula due to appendicitis. A 42-year-old man was admitted with complaints of low abdominal pain, distension, and a chilling sense for 1 month. On physical examination, the patient had right low-quadrant abdominal tenderness and rebound tenderness. However, the patient had no fever, and the WBC count was 8,900/$mm^{3}$. On colonoscopy and barium study, the patient was diagnosed as having an appendico-sigmoid fistula due to appendicitis. An appendectomy and segmental resection of the sigmoid colon was done.