The authors carried out experimental studies on 23 dogs to examine changes, which occurred in the wall of the anastomosed ileum and the large intestine as well as in some organs after performing traversed anastomoses. The results were evaluated on the basis of clinico-experimental observations, on the changes in laboratory indices (complete blood picture, proteinogram, ionogram, blood urea and cholesterol), in microflora and in bioelectrical, activity. They examined ionic absorption in the large intestine excluded from the passage. An analysis was made on the pathologo-histological finding in the colon, anastomised ileum, liver and spleen, kidneys, heart, pancreas. The authors come to conclusions, useful to the physicians performing large intestine surgery.