The aim of this study was to create an experimental model of type 2 diabetes mellitus in laboratory rats and to study the morphological state of colon tissue structures after mini-gastroshunt (MGS, one-anastomosis gastric bypass) surgery. 40 male Wistar rats with a body weight of 180-220 g were used in the study. After the diabetes model was confirmed, mini-gastroshunt surgery was performed in the experimental group. After mini-gastroshunt surgery, animals were removed from the experiment on days 1, 3, 7, 14 and 30, and material was taken from the distal sections of the colon. The material was fixed in 10% neutral formalin, embedded in paraffin, and sections were stained with hematoxylin-eosin, Van Gieson and Mallory to identify connective tissue. Electron microscopy was used for ultrastructural analysis. The results of the study show that mini-gastroshunt surgery does not cause irreversible damage to the colon even in the setting of type 2 diabetes, but rather activates compensatory-adaptive mechanisms.