Background: It is sometimes necessary to translocate part of the gastrointestinal tract into the site of the organ earlier resected. This occurs after total esophageal, stomach or colon resection, which can lead to disturbances in the anatomical and functional balance of the gastrointestinal tract and the body as a whole. The aim of this study was to evaluate the effects of different resective surgical procedures performed on the proximal and distal GI tract in terms of total body weight, selected liver function tests, and ultrastructural changes in the liver in laboratory rats.Material/Methods: The total of 57 resective procedures consisted of 31 total gastric and 26 total colon resections. The control group consisted of 12 animals on which only laparotomy was performed. Body weight, stool character, and the general condition of the animals were evaluated from the time of the operation. Twenty-six blood samples were collected for analysis of hemoglobin, total plasma protein, and liver aminotransferases levels. Thirty liver tissue samples from the 3 groups were taken and examined.Results: We observed statistically significant decreases in total body weight, hemoglobin, and total plasma protein levels in the group where reconstructive procedures following gastrectomy were performed. In the group in which reconstructive procedures followed colectomy, a statistically significant decrease in total body weight was observed. Aminotransferase level changes were neither characteristic nor significantly different in any of the three groups involved in the investigation.Conclusions: Abnormalities of liver structure were observed at the ultrastructural level. Any correlation between these changes, general condition, and selected biochemical parameters requires further controlled clinical and experimental studies.

Keywords: Alanine Transaminase - blood, Aspartate Aminotransferases - blood, Alanine Transaminase - blood, Aspartate Aminotransferases - blood, Biological Markers - blood, Blood Proteins - analysis, Body Weight, Colectomy - methods, Cytoplasm - ultrastructure, Gastrectomy - methods, Hemoglobins - analysis, Hepatocytes - ultrastructure, Liver - ultrastructure, Liver Function Tests, Mitochondria, Liver - ultrastructure, Postoperative Period, Rats, Wistar, Reconstructive Surgical Procedures - methods