Experiments on 7 Wistar rats were performed to verify the hypothesis on significance of impaired process of feces evacuation from colorectal intestine. Local damage of somatic and visceral nerves in the anus region resulted in violation of defecation process and accumulation of feces in expanded colorectal parts of intestine in one week of observation. Pathological changes in tissue structure in muscular and submuscular layers of intestine together with transformations in corresponding nerve ganglia were revealed in one and two weeks by histological methods. Such changes in experimental model are associated with typical events in daily life of a person suffering from chronic constipation. Persistent chronic constipation leads to systematic damage of tissues in colorectal region followed by development of pathological processes and formation of inflammatory and precancerous processes in colorectal region.