Ultrastructural changes in the gut autonomic nervous system following laxative abuse and in other conditions.

Electronmicroscopical studies have been carried out on colonic biopsies from patients with long-term laxative abuse, amyloidosis, diabetic autonomic neuropathy or chronic inflammatory bowel disease. The results of these investigations indicate that submucosal nerve fibres are damaged to an extent dependent upon the intensity of the toxic agent. The main pathological features range from distension or ballooning of axons, reduction of nerve-specific cell structures and increase in lysosomes to a total degeneration of whole nerve fibres. While the degenerative process is uniform, differentiation between disease states can be made on the basis of specific additional lesions such as the presence of typical amyloid fibrils, diabetic microangiopathy or the inflammatory process in inflammatory bowel disease. No changes were found in Whipple's disease or gluten-sensitive enteropathy. It is concluded that the structural alterations may provide a morphological explanation for the disturbances in gut motility, as an intact intramural nervous system is a necessary prerequisite for the regular coordination of normal peristalsis.