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. Investigations into the causes of pain have been limited by changes in the dynamics with the progression of the disease process, limitations in studying functional and morphological changes of the pancreas in the clinical setting, and the psychosomatic profile of patients. Many of these patients are addicted to alcohol, and suffer from personality disorders. The difficulty in quantifying pain, which is at best subjective, further compounds the issue, especially when assessing the efficacy of treatment.