Complications after digestive surgery can be diverse and serious, requiring careful monitoring and prompt intervention. These complications can affect different parts of the digestive system and include mechanical, infectious, metabolic and thromboembolic problems. Some of the most common complications, which we will talk more about below, are pressure ulcers, urinary infections, bacteria, pneumonia, anastomosis dehiscence, wound dehiscence, bleeding and pleural effusions. The aim of this research is to investigate the occurrence of postoperative complications in the only Intensive care unit of the Department of Digestive Surgery, to determine which is the biggest complication, and to investigate whether there is a positive relationship between complications and the patient's age. The research was conducted during May and June 2024 at KBC Rijeka, in the Intensive care unit of the Institute for Digestive Surgery. 200 patients who were hospitalized from December 2023 to June 2024 participated in the research. Data for this research were collected anonymously from the Rijeka Clinical Hospital Center database from the IBIS system. The research results showed that 2 hypotheses were refuted, and one hypothesis was accepted. Hypothesis 1 proves that complications of patients in the Intensive care unit of the Department of Digestive Surgery occur with a frequency of less than 50%, hypothesis 2 proves that the most frequent complication in the same department is pleural effusion, and hypothesis 3 proves a positive correlation between the age of patients and complications in the Intensive care unit care of the Institute for Digestive Surgery.