The following paper presents the case of a 40-year-old patient staying in our Clinic between 2 March 2010 and 12 March 2010 due to the symptoms of permeable occlusion of gastrointestinal tract. This is a patient with a several weeks' history of non-specific abdominal pain, vomiting and significant weight loss (ca 20 kg). Until recently he has not suffered from any serious illnesses. In the performed abdominal ultrasound, gastroscopy and colonoscopy no pathology was affirmed. CT scan with intravenous and oral contrast showed significantly widened intestinal loops with residual liquid matter in the stomach, duodenum and a part of the jejunum without any distinguishing pathological mass, and also single mesenteric lymph nodes and para-aortic nodes enlarged to the size of 12 mm. The patient was qualified for laparatomy. During the surgery, a 4-cm tumour of the jejunum, concentrically narrowing intestinal lumen was found. Segmental resection of the small intestine was performed with side to side anastomosis with the use of a linear stapler. Currently the general condition of the patient is good, without any ailments, and the patient is undergoing systemic treatment.