Pathogenesis of pain in chronic pancreatitis: ongoing enigma.

The pathogenesis of pain in chronic pancreatitis remains an enigma. The cause of pain is almost certainly multifactorial and may vary at different stages of the disease process. These factors may include the release of excessive oxygen-derived free radicals, tissue hypoxia and acidosis, inflammatory infiltration with influx of pain transmittent substances into damaged nerve ends, and the development of pancreatic ductal and tissue fluid hypertension due to morphological changes of the pancreas.