Histological Changes in the Intestinal Wall in Experimental Obstructive Ileus: Experimental Animal Study

Background: Patients with obstructive bowel obstruction often develop severe infections, which can lead to death in 45-88% of cases. These complications are thought to be caused by bacteria in the intestine. However, treatments that affect these bacteria have not helped to reduce the number of complications. It is important to find other possible sources of infection in intestinal obstruction. The experiment was done to study how the intestinal wall changes during 48 hours of obstruction. Methods: The experiment was conducted on 13 white rats. The animals were separated into two groups. In the first (control) group, 5 rats experienced a laparotomy (abdominal incision) without affecting the intestines. In the second group, eight rats had their small intestine ligated after laparotomy to cause a complete blockage. Then the abdomen was sutured and after a specific time, the intestines were examined after 12, 24, 36 and 48 hours. Results: The results showed no changes in the control group. The histological examination revealed that the average thickness of the intestinal mucosa was 0.48±0.02 mm and the muscle layer was 0.92±0.02 mm. Healthy enterocytes with a clear structure were observed. In the group with intestinal obstruction, after 12 hours, the intestine dilated to 6-9 mm above the obstruction site and fluid appeared in the abdominal cavity. After 48 hours, the intestine became 2.5 times wider, blue-purple in colour and cloudy in fluid. The study showed that there were no changes in the control group. However, in the group with obstructive obstruction, purulent inflammation of the intestine began within 12 hours. It first appeared on the mucous membrane because the protective layer of the villi was damaged. Then, the inflammation spreads to the muscle and serous layers. Inflammation happened not only at the place of the blockage but also in the part of the intestine above it. Conclusions: The source of purulent complications in intestinal obstruction involves both intestinal microbes and structural damage to the bowel wall above the blockage. These findings underscore the need for early surgical intervention and strategies to protect the intestinal barrier, not just target the microbiota.