We describe a rare case of tuberculosis with mainly gastrointestinal problems. The 52-year-aged female patient came to hospital with unclear pain in the lower abdomen and ascites that was refractory to therapy. The computed tomography of the thorax showed right-sided confluating lymphoid nodes, the CT of the abdomen showed ascites and nodular structures near the coecum. Tissue samples were taken from the mucosa of the colon, the inflammatory altered peritoneum, the left bronchus of the upper lobe and the confluating lymphoid nodes in the mediastinum during colonoscopy, diagnostic laparoscopy and bronchoscopy. The samples from the peritoneum showed granulomas with caseating necroses in histological slices. Mycobacterium tuberculosis was detected by PCR in the tissue samples from the lymphoid tissue of the mediastinum. Furthermore, Mycobacterium tuberculosis grew in cultures from samples of the abdominal ascites. The symptoms and pathological findings improved under a therapy comprising isoniazid, rifampicin, ethambutol and pyrazinamid.