1. Department of General, Transplant and Liver Surgery, Medical University of Warsaw, Warsaw, Poland
2. Department of Gastroenterology and Internal Medicine, SPWSZ Hospital, Szczecin, Poland
3. Department of Gastroenterology, Hospital of the Ministry of Internal Affairs in Szczecin, Poland
4. Department of Plastic, Endocrine and General Surgery, Pomeranian Medical University, Szczecin, Poland