We present a 25-year-old, HIV-negative patient from Kosovo, with no significant past medical history, who was admitted to a local hospital for nonspecific upper abdominal discomfort. He was transferred to us after a retroperitoneal mass with contact to the right colonic flexure had been found during workup. Colonoscopy demonstrated an edemateous area with a central fistula in the right flexure, and histology showed caseous necrosis. Although neither bacteriology nor histology could detect any germs, gastrointestinal tuberculosis seemed to be very probable. Laparotomy with a segmental resection of the colon was performed to remove the fistula-bearing segment, and histologic examination of the resected specimen confirmed the intraoperative suspect of a retroperitoneal colonic perforation. Again, all cultures from the specimen were negative for tuberculosis, but polymerase chain reaction of a regional lymph node revealed acid-fast bacilli of the Mycobacterium tuberculosis/bovis species. Although the patient had no other sites of tuberculosis infection like pulmonary or urinary, he received adjuvant standard tuberculosis treatment for six months. At control examination one year after the operation, the patient was free of recurrence and in very good general condition. We report this extremely rare presentation of gastrointestinal tuberculosis to sensitize physicians to tuberculosis again, because incidence rates are increasing and this disease will certainly play a more important role in the future.