An 84-year-old woman was seen at the hospital because of a subcutaneous abscess and was admitted for treatment and close examination. Because of senile dementia, she hardly complained of subjective symptoms such as pain. On physical examination, there was a subcutaneous abscess with reddening and edema in the right anterior thoracic region. With an incision of the abscess, discharge of pus was observed. Pus discharge occurred from subcutaneous space between the right 10th and 11th ribs to form a fistula. A fistulography visualized the gallbladder and subsequently the colon. There were stones in the gallbladder. Cholelithiasis associated with an external fistula of the gallbladder and a fistula between the gallbladder and colon was diagnosed. A cholecystectomy and a partial excision of the transverse colon were performed.