The fine structure of colonic submucosal nerves in patients with chronic laxative abuse.

Ultrastructural studies of colonic biopsies from patients with a history of long-term laxative abuse, predominantly with stimulant cathartics such as anthraquinone derivatives or bisacodyl, indicated that submucosal nerve fibres may be severely damaged in relation to dosage and time of addiction. The main pathological features found were ballooning of axons, reduction of nerve-specific cell organelles, lysosomal activity, and increase of melanin-loaded macrophages. Morphometric analysis revealed a significant increase (P less than 0.01) in axonal area, with simultaneous reduction of neurotubules. Nerve endings showed a significant decrease of neurosecretory granules when compared with those of normals. It is concluded that these alterations might be a morphological correlation to the clinically evident disturbance of gut motility in patients with chronic laxative abuse, because the intact enteric plexus system is a prerequisite for coordination of normal gut peristalsis.