Sigmoido-gluteal fistula due to diverticulitis: report of a rare complication

introduction: Complicated diverticulitis of the colon is characterized by its association with abscesses, bleeding, stenosis, perforation, obstruction or fistula. We report a case of spontaneous sigmoidocutaneous fistula due to diverticulitis that appeared in an unusual location in the gluteal region. Clinical case: A 59-year-old male patient presented an inflammatory wound in the left buttock without response to conservative medical treatment. Fistulography, colonoscopy, barium enema and computed tomography showed a sigmoidocutaneous fistula of the left buttock due to diverticulitis. Biopsy of the lesion ruled out malignancy. Elective sigmoid resection was performed with primary colorectal anastomosis, partial fistulectomy and injection of a fibrin sealant in the residual tract. discussion: Colocutaneous fistulas due to diverticulitis are relatively rare. We report a spontaneous fistula with origin in a single diverticulum in the sigmoid colon that drained through the piriform fossa of the pelvic floor to the skin of the left buttock. Conclusions: A high index of suspicion is necessary in order to not confuse the colo-buttock fistula with local abscesses.